diff --git a/crates/wasmparser/src/validator/component_types.rs b/crates/wasmparser/src/validator/component_types.rs
index 789f9b2c97..53d0f820e6 100644
--- a/crates/wasmparser/src/validator/component_types.rs
+++ b/crates/wasmparser/src/validator/component_types.rs
@@ -25,6 +25,9 @@ use core::{
 /// Functions that exceed this limit will instead pass parameters indirectly from
 /// linear memory via a single pointer parameter.
 const MAX_FLAT_FUNC_PARAMS: usize = 16;
+/// The maximum number of parameters in the canonical ABI that can be passed by
+/// value in async function imports/exports.
+const MAX_FLAT_ASYNC_PARAMS: usize = 4;
 /// The maximum number of results in the canonical ABI that can be returned by a function.
 ///
 /// Functions that exceed this limit have their results written to linear memory via an
@@ -931,15 +934,7 @@ impl ComponentFuncType {
         let mut sig = LoweredSignature::default();
 
         if abi == Abi::Lower && options.concurrency.is_async() {
-            for _ in 0..2 {
-                sig.params.assert_push(ValType::I32);
-            }
-            sig.results.assert_push(ValType::I32);
-            options.require_memory(offset)?;
-            if self.result.is_some_and(|ty| ty.contains_ptr(types)) {
-                options.require_realloc(offset)?;
-            }
-            return Ok(sig.into_func_type());
+            sig.params.max = MAX_FLAT_ASYNC_PARAMS;
         }
 
         for (_, ty) in self.params.iter() {
@@ -975,9 +970,6 @@ impl ComponentFuncType {
         }
 
         match (abi, options.concurrency) {
-            (Abi::Lower, Concurrency::Async { .. }) => {
-                unreachable!("special-cased at the start of the function")
-            }
             (Abi::Lower | Abi::Lift, Concurrency::Sync) => {
                 if let Some(ty) = &self.result {
                     // Results of lowered functions that contains pointers must be
@@ -1006,10 +998,19 @@ impl ComponentFuncType {
                     }
                 }
             }
-            (Abi::Lift, Concurrency::Async { callback: Some(_) }) => {
+            (Abi::Lower, Concurrency::Async { callback: _ }) => {
+                if self.result.is_some() {
+                    sig.params.max = MAX_LOWERED_TYPES;
+                    sig.params.assert_push(ValType::I32);
+                    options.require_memory(offset)?;
+                }
                 sig.results.assert_push(ValType::I32);
             }
-            (Abi::Lift, Concurrency::Async { callback: None }) => {}
+            (Abi::Lift, Concurrency::Async { callback }) => {
+                if callback.is_some() {
+                    sig.results.assert_push(ValType::I32);
+                }
+            }
         }
 
         Ok(sig.into_func_type())
diff --git a/crates/wit-component/tests/components/async-import/component.wat b/crates/wit-component/tests/components/async-import/component.wat
index 4036fab673..af47790d81 100644
--- a/crates/wit-component/tests/components/async-import/component.wat
+++ b/crates/wit-component/tests/components/async-import/component.wat
@@ -9,7 +9,7 @@
   (type (;1;) (func (param "s" string) (result string)))
   (import "foo" (func (;0;) (type 1)))
   (core module (;0;)
-    (type (;0;) (func (param i32 i32) (result i32)))
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
     (type (;1;) (func (param i32 i32 i32)))
     (type (;2;) (func (param i32 i32 i32 i32) (result i32)))
     (import "$root" "[async-lower]foo" (func (;0;) (type 0)))
@@ -28,7 +28,7 @@
     )
   )
   (core module (;1;)
-    (type (;0;) (func (param i32 i32) (result i32)))
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
     (type (;1;) (func (param i32 i32 i32)))
     (table (;0;) 4 4 funcref)
     (export "0" (func $"indirect-$root-[async-lower]foo"))
@@ -36,9 +36,10 @@
     (export "2" (func $"indirect-foo:foo/bar-[async-lower]foo"))
     (export "3" (func $indirect-foo:foo/bar-foo))
     (export "$imports" (table 0))
-    (func $"indirect-$root-[async-lower]foo" (;0;) (type 0) (param i32 i32) (result i32)
+    (func $"indirect-$root-[async-lower]foo" (;0;) (type 0) (param i32 i32 i32) (result i32)
       local.get 0
       local.get 1
+      local.get 2
       i32.const 0
       call_indirect (type 0)
     )
@@ -49,9 +50,10 @@
       i32.const 1
       call_indirect (type 1)
     )
-    (func $"indirect-foo:foo/bar-[async-lower]foo" (;2;) (type 0) (param i32 i32) (result i32)
+    (func $"indirect-foo:foo/bar-[async-lower]foo" (;2;) (type 0) (param i32 i32 i32) (result i32)
       local.get 0
       local.get 1
+      local.get 2
       i32.const 2
       call_indirect (type 0)
     )
@@ -67,7 +69,7 @@
     )
   )
   (core module (;2;)
-    (type (;0;) (func (param i32 i32) (result i32)))
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
     (type (;1;) (func (param i32 i32 i32)))
     (import "" "0" (func (;0;) (type 0)))
     (import "" "1" (func (;1;) (type 1)))
diff --git a/crates/wit-component/tests/components/async-import/module.wat b/crates/wit-component/tests/components/async-import/module.wat
index 723fea947c..df10e1cc4e 100644
--- a/crates/wit-component/tests/components/async-import/module.wat
+++ b/crates/wit-component/tests/components/async-import/module.wat
@@ -1,6 +1,6 @@
 (module
-  (func (import "$root" "[async-lower]foo") (param i32 i32) (result i32))
-  (func (import "foo:foo/bar" "[async-lower]foo") (param i32 i32) (result i32))
+  (func (import "$root" "[async-lower]foo") (param i32 i32 i32) (result i32))
+  (func (import "foo:foo/bar" "[async-lower]foo") (param i32 i32 i32) (result i32))
   (func (import "$root" "foo") (param i32 i32 i32))
   (func (import "foo:foo/bar" "foo") (param i32 i32 i32))
   (memory (export "memory") 1)
diff --git a/crates/wit-component/tests/components/async-streams-and-futures/component.wat b/crates/wit-component/tests/components/async-streams-and-futures/component.wat
index 6e1a263019..c377fea50d 100644
--- a/crates/wit-component/tests/components/async-streams-and-futures/component.wat
+++ b/crates/wit-component/tests/components/async-streams-and-futures/component.wat
@@ -15,99 +15,99 @@
   (type (;4;) (func (param "x" 2) (param "y" u32) (result 3)))
   (import "foo" (func (;0;) (type 4)))
   (core module (;0;)
-    (type (;0;) (func (param i32 i32) (result i32)))
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
     (type (;1;) (func (result i64)))
-    (type (;2;) (func (param i32 i32 i32) (result i32)))
-    (type (;3;) (func (param i32) (result i32)))
-    (type (;4;) (func (param i32)))
+    (type (;2;) (func (param i32) (result i32)))
+    (type (;3;) (func (param i32)))
+    (type (;4;) (func (param i32 i32) (result i32)))
     (type (;5;) (func (param i32 i32)))
     (type (;6;) (func (param i32 i32 i32 i32) (result i32)))
     (import "$root" "[async-lower]foo" (func (;0;) (type 0)))
     (import "foo:foo/bar" "[async-lower]foo" (func (;1;) (type 0)))
     (import "$root" "[stream-new-2]foo" (func (;2;) (type 1)))
-    (import "$root" "[stream-read-2]foo" (func (;3;) (type 2)))
-    (import "$root" "[stream-write-2]foo" (func (;4;) (type 2)))
-    (import "$root" "[stream-cancel-read-2]foo" (func (;5;) (type 3)))
-    (import "$root" "[stream-cancel-write-2]foo" (func (;6;) (type 3)))
-    (import "$root" "[stream-close-readable-2]foo" (func (;7;) (type 4)))
-    (import "$root" "[stream-close-writable-2]foo" (func (;8;) (type 4)))
+    (import "$root" "[stream-read-2]foo" (func (;3;) (type 0)))
+    (import "$root" "[stream-write-2]foo" (func (;4;) (type 0)))
+    (import "$root" "[stream-cancel-read-2]foo" (func (;5;) (type 2)))
+    (import "$root" "[stream-cancel-write-2]foo" (func (;6;) (type 2)))
+    (import "$root" "[stream-close-readable-2]foo" (func (;7;) (type 3)))
+    (import "$root" "[stream-close-writable-2]foo" (func (;8;) (type 3)))
     (import "foo:foo/bar" "[stream-new-2]foo" (func (;9;) (type 1)))
-    (import "foo:foo/bar" "[stream-read-2]foo" (func (;10;) (type 2)))
-    (import "foo:foo/bar" "[stream-write-2]foo" (func (;11;) (type 2)))
-    (import "foo:foo/bar" "[stream-cancel-read-2]foo" (func (;12;) (type 3)))
-    (import "foo:foo/bar" "[stream-cancel-write-2]foo" (func (;13;) (type 3)))
-    (import "foo:foo/bar" "[stream-close-readable-2]foo" (func (;14;) (type 4)))
-    (import "foo:foo/bar" "[stream-close-writable-2]foo" (func (;15;) (type 4)))
+    (import "foo:foo/bar" "[stream-read-2]foo" (func (;10;) (type 0)))
+    (import "foo:foo/bar" "[stream-write-2]foo" (func (;11;) (type 0)))
+    (import "foo:foo/bar" "[stream-cancel-read-2]foo" (func (;12;) (type 2)))
+    (import "foo:foo/bar" "[stream-cancel-write-2]foo" (func (;13;) (type 2)))
+    (import "foo:foo/bar" "[stream-close-readable-2]foo" (func (;14;) (type 3)))
+    (import "foo:foo/bar" "[stream-close-writable-2]foo" (func (;15;) (type 3)))
     (import "$root" "[future-new-0]foo" (func (;16;) (type 1)))
-    (import "$root" "[future-read-0]foo" (func (;17;) (type 0)))
-    (import "$root" "[future-write-0]foo" (func (;18;) (type 0)))
-    (import "$root" "[future-cancel-read-0]foo" (func (;19;) (type 3)))
-    (import "$root" "[future-cancel-write-0]foo" (func (;20;) (type 3)))
-    (import "$root" "[future-close-readable-0]foo" (func (;21;) (type 4)))
-    (import "$root" "[future-close-writable-0]foo" (func (;22;) (type 4)))
+    (import "$root" "[future-read-0]foo" (func (;17;) (type 4)))
+    (import "$root" "[future-write-0]foo" (func (;18;) (type 4)))
+    (import "$root" "[future-cancel-read-0]foo" (func (;19;) (type 2)))
+    (import "$root" "[future-cancel-write-0]foo" (func (;20;) (type 2)))
+    (import "$root" "[future-close-readable-0]foo" (func (;21;) (type 3)))
+    (import "$root" "[future-close-writable-0]foo" (func (;22;) (type 3)))
     (import "foo:foo/bar" "[future-new-0]foo" (func (;23;) (type 1)))
-    (import "foo:foo/bar" "[future-read-0]foo" (func (;24;) (type 0)))
-    (import "foo:foo/bar" "[future-write-0]foo" (func (;25;) (type 0)))
-    (import "foo:foo/bar" "[future-cancel-read-0]foo" (func (;26;) (type 3)))
-    (import "foo:foo/bar" "[future-cancel-write-0]foo" (func (;27;) (type 3)))
-    (import "foo:foo/bar" "[future-close-readable-0]foo" (func (;28;) (type 4)))
-    (import "foo:foo/bar" "[future-close-writable-0]foo" (func (;29;) (type 4)))
+    (import "foo:foo/bar" "[future-read-0]foo" (func (;24;) (type 4)))
+    (import "foo:foo/bar" "[future-write-0]foo" (func (;25;) (type 4)))
+    (import "foo:foo/bar" "[future-cancel-read-0]foo" (func (;26;) (type 2)))
+    (import "foo:foo/bar" "[future-cancel-write-0]foo" (func (;27;) (type 2)))
+    (import "foo:foo/bar" "[future-close-readable-0]foo" (func (;28;) (type 3)))
+    (import "foo:foo/bar" "[future-close-writable-0]foo" (func (;29;) (type 3)))
     (import "$root" "[future-new-1]foo" (func (;30;) (type 1)))
-    (import "$root" "[future-read-1]foo" (func (;31;) (type 0)))
-    (import "$root" "[future-write-1]foo" (func (;32;) (type 0)))
-    (import "$root" "[future-cancel-read-1]foo" (func (;33;) (type 3)))
-    (import "$root" "[future-cancel-write-1]foo" (func (;34;) (type 3)))
-    (import "$root" "[future-close-readable-1]foo" (func (;35;) (type 4)))
-    (import "$root" "[future-close-writable-1]foo" (func (;36;) (type 4)))
+    (import "$root" "[future-read-1]foo" (func (;31;) (type 4)))
+    (import "$root" "[future-write-1]foo" (func (;32;) (type 4)))
+    (import "$root" "[future-cancel-read-1]foo" (func (;33;) (type 2)))
+    (import "$root" "[future-cancel-write-1]foo" (func (;34;) (type 2)))
+    (import "$root" "[future-close-readable-1]foo" (func (;35;) (type 3)))
+    (import "$root" "[future-close-writable-1]foo" (func (;36;) (type 3)))
     (import "foo:foo/bar" "[future-new-1]foo" (func (;37;) (type 1)))
-    (import "foo:foo/bar" "[future-read-1]foo" (func (;38;) (type 0)))
-    (import "foo:foo/bar" "[future-write-1]foo" (func (;39;) (type 0)))
-    (import "foo:foo/bar" "[future-cancel-read-1]foo" (func (;40;) (type 3)))
-    (import "foo:foo/bar" "[future-cancel-write-1]foo" (func (;41;) (type 3)))
-    (import "foo:foo/bar" "[future-close-readable-1]foo" (func (;42;) (type 4)))
-    (import "foo:foo/bar" "[future-close-writable-1]foo" (func (;43;) (type 4)))
+    (import "foo:foo/bar" "[future-read-1]foo" (func (;38;) (type 4)))
+    (import "foo:foo/bar" "[future-write-1]foo" (func (;39;) (type 4)))
+    (import "foo:foo/bar" "[future-cancel-read-1]foo" (func (;40;) (type 2)))
+    (import "foo:foo/bar" "[future-cancel-write-1]foo" (func (;41;) (type 2)))
+    (import "foo:foo/bar" "[future-close-readable-1]foo" (func (;42;) (type 3)))
+    (import "foo:foo/bar" "[future-close-writable-1]foo" (func (;43;) (type 3)))
     (import "[export]$root" "[stream-new-2]foo" (func (;44;) (type 1)))
-    (import "[export]$root" "[stream-read-2]foo" (func (;45;) (type 2)))
-    (import "[export]$root" "[stream-write-2]foo" (func (;46;) (type 2)))
-    (import "[export]$root" "[stream-cancel-read-2]foo" (func (;47;) (type 3)))
-    (import "[export]$root" "[stream-cancel-write-2]foo" (func (;48;) (type 3)))
-    (import "[export]$root" "[stream-close-readable-2]foo" (func (;49;) (type 4)))
-    (import "[export]$root" "[stream-close-writable-2]foo" (func (;50;) (type 4)))
+    (import "[export]$root" "[stream-read-2]foo" (func (;45;) (type 0)))
+    (import "[export]$root" "[stream-write-2]foo" (func (;46;) (type 0)))
+    (import "[export]$root" "[stream-cancel-read-2]foo" (func (;47;) (type 2)))
+    (import "[export]$root" "[stream-cancel-write-2]foo" (func (;48;) (type 2)))
+    (import "[export]$root" "[stream-close-readable-2]foo" (func (;49;) (type 3)))
+    (import "[export]$root" "[stream-close-writable-2]foo" (func (;50;) (type 3)))
     (import "[export]foo:foo/bar" "[stream-new-2]foo" (func (;51;) (type 1)))
-    (import "[export]foo:foo/bar" "[stream-read-2]foo" (func (;52;) (type 2)))
-    (import "[export]foo:foo/bar" "[stream-write-2]foo" (func (;53;) (type 2)))
-    (import "[export]foo:foo/bar" "[stream-cancel-read-2]foo" (func (;54;) (type 3)))
-    (import "[export]foo:foo/bar" "[stream-cancel-write-2]foo" (func (;55;) (type 3)))
-    (import "[export]foo:foo/bar" "[stream-close-readable-2]foo" (func (;56;) (type 4)))
-    (import "[export]foo:foo/bar" "[stream-close-writable-2]foo" (func (;57;) (type 4)))
+    (import "[export]foo:foo/bar" "[stream-read-2]foo" (func (;52;) (type 0)))
+    (import "[export]foo:foo/bar" "[stream-write-2]foo" (func (;53;) (type 0)))
+    (import "[export]foo:foo/bar" "[stream-cancel-read-2]foo" (func (;54;) (type 2)))
+    (import "[export]foo:foo/bar" "[stream-cancel-write-2]foo" (func (;55;) (type 2)))
+    (import "[export]foo:foo/bar" "[stream-close-readable-2]foo" (func (;56;) (type 3)))
+    (import "[export]foo:foo/bar" "[stream-close-writable-2]foo" (func (;57;) (type 3)))
     (import "[export]$root" "[future-new-0]foo" (func (;58;) (type 1)))
-    (import "[export]$root" "[future-read-0]foo" (func (;59;) (type 0)))
-    (import "[export]$root" "[future-write-0]foo" (func (;60;) (type 0)))
-    (import "[export]$root" "[future-cancel-read-0]foo" (func (;61;) (type 3)))
-    (import "[export]$root" "[future-cancel-write-0]foo" (func (;62;) (type 3)))
-    (import "[export]$root" "[future-close-readable-0]foo" (func (;63;) (type 4)))
-    (import "[export]$root" "[future-close-writable-0]foo" (func (;64;) (type 4)))
+    (import "[export]$root" "[future-read-0]foo" (func (;59;) (type 4)))
+    (import "[export]$root" "[future-write-0]foo" (func (;60;) (type 4)))
+    (import "[export]$root" "[future-cancel-read-0]foo" (func (;61;) (type 2)))
+    (import "[export]$root" "[future-cancel-write-0]foo" (func (;62;) (type 2)))
+    (import "[export]$root" "[future-close-readable-0]foo" (func (;63;) (type 3)))
+    (import "[export]$root" "[future-close-writable-0]foo" (func (;64;) (type 3)))
     (import "[export]foo:foo/bar" "[future-new-0]foo" (func (;65;) (type 1)))
-    (import "[export]foo:foo/bar" "[future-read-0]foo" (func (;66;) (type 0)))
-    (import "[export]foo:foo/bar" "[future-write-0]foo" (func (;67;) (type 0)))
-    (import "[export]foo:foo/bar" "[future-cancel-read-0]foo" (func (;68;) (type 3)))
-    (import "[export]foo:foo/bar" "[future-cancel-write-0]foo" (func (;69;) (type 3)))
-    (import "[export]foo:foo/bar" "[future-close-readable-0]foo" (func (;70;) (type 4)))
-    (import "[export]foo:foo/bar" "[future-close-writable-0]foo" (func (;71;) (type 4)))
+    (import "[export]foo:foo/bar" "[future-read-0]foo" (func (;66;) (type 4)))
+    (import "[export]foo:foo/bar" "[future-write-0]foo" (func (;67;) (type 4)))
+    (import "[export]foo:foo/bar" "[future-cancel-read-0]foo" (func (;68;) (type 2)))
+    (import "[export]foo:foo/bar" "[future-cancel-write-0]foo" (func (;69;) (type 2)))
+    (import "[export]foo:foo/bar" "[future-close-readable-0]foo" (func (;70;) (type 3)))
+    (import "[export]foo:foo/bar" "[future-close-writable-0]foo" (func (;71;) (type 3)))
     (import "[export]$root" "[future-new-1]foo" (func (;72;) (type 1)))
-    (import "[export]$root" "[future-read-1]foo" (func (;73;) (type 0)))
-    (import "[export]$root" "[future-write-1]foo" (func (;74;) (type 0)))
-    (import "[export]$root" "[future-cancel-read-1]foo" (func (;75;) (type 3)))
-    (import "[export]$root" "[future-cancel-write-1]foo" (func (;76;) (type 3)))
-    (import "[export]$root" "[future-close-readable-1]foo" (func (;77;) (type 4)))
-    (import "[export]$root" "[future-close-writable-1]foo" (func (;78;) (type 4)))
+    (import "[export]$root" "[future-read-1]foo" (func (;73;) (type 4)))
+    (import "[export]$root" "[future-write-1]foo" (func (;74;) (type 4)))
+    (import "[export]$root" "[future-cancel-read-1]foo" (func (;75;) (type 2)))
+    (import "[export]$root" "[future-cancel-write-1]foo" (func (;76;) (type 2)))
+    (import "[export]$root" "[future-close-readable-1]foo" (func (;77;) (type 3)))
+    (import "[export]$root" "[future-close-writable-1]foo" (func (;78;) (type 3)))
     (import "[export]foo:foo/bar" "[future-new-1]foo" (func (;79;) (type 1)))
-    (import "[export]foo:foo/bar" "[future-read-1]foo" (func (;80;) (type 0)))
-    (import "[export]foo:foo/bar" "[future-write-1]foo" (func (;81;) (type 0)))
-    (import "[export]foo:foo/bar" "[future-cancel-read-1]foo" (func (;82;) (type 3)))
-    (import "[export]foo:foo/bar" "[future-cancel-write-1]foo" (func (;83;) (type 3)))
-    (import "[export]foo:foo/bar" "[future-close-readable-1]foo" (func (;84;) (type 4)))
-    (import "[export]foo:foo/bar" "[future-close-writable-1]foo" (func (;85;) (type 4)))
+    (import "[export]foo:foo/bar" "[future-read-1]foo" (func (;80;) (type 4)))
+    (import "[export]foo:foo/bar" "[future-write-1]foo" (func (;81;) (type 4)))
+    (import "[export]foo:foo/bar" "[future-cancel-read-1]foo" (func (;82;) (type 2)))
+    (import "[export]foo:foo/bar" "[future-cancel-write-1]foo" (func (;83;) (type 2)))
+    (import "[export]foo:foo/bar" "[future-close-readable-1]foo" (func (;84;) (type 3)))
+    (import "[export]foo:foo/bar" "[future-close-writable-1]foo" (func (;85;) (type 3)))
     (memory (;0;) 1)
     (export "[async-lift-stackful]foo" (func 86))
     (export "[async-lift-stackful]foo:foo/bar#foo" (func 87))
@@ -128,7 +128,7 @@
     )
   )
   (core module (;1;)
-    (type (;0;) (func (param i32 i32) (result i32)))
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
     (type (;1;) (func (param i32 i32 i32) (result i32)))
     (type (;2;) (func (param i32 i32) (result i32)))
     (table (;0;) 26 26 funcref)
@@ -159,9 +159,10 @@
     (export "24" (func $"[export]foo:foo/bar-[future-read-1]foo"))
     (export "25" (func $"[export]foo:foo/bar-[future-write-1]foo"))
     (export "$imports" (table 0))
-    (func $"indirect-$root-[async-lower]foo" (;0;) (type 0) (param i32 i32) (result i32)
+    (func $"indirect-$root-[async-lower]foo" (;0;) (type 0) (param i32 i32 i32) (result i32)
       local.get 0
       local.get 1
+      local.get 2
       i32.const 0
       call_indirect (type 0)
     )
@@ -203,9 +204,10 @@
       i32.const 6
       call_indirect (type 2)
     )
-    (func $"indirect-foo:foo/bar-[async-lower]foo" (;7;) (type 0) (param i32 i32) (result i32)
+    (func $"indirect-foo:foo/bar-[async-lower]foo" (;7;) (type 0) (param i32 i32 i32) (result i32)
       local.get 0
       local.get 1
+      local.get 2
       i32.const 7
       call_indirect (type 0)
     )
@@ -328,7 +330,7 @@
     )
   )
   (core module (;2;)
-    (type (;0;) (func (param i32 i32) (result i32)))
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
     (type (;1;) (func (param i32 i32 i32) (result i32)))
     (type (;2;) (func (param i32 i32) (result i32)))
     (import "" "0" (func (;0;) (type 0)))
diff --git a/crates/wit-component/tests/components/async-streams-and-futures/module.wat b/crates/wit-component/tests/components/async-streams-and-futures/module.wat
index 2f2603e656..60fe1bf35d 100644
--- a/crates/wit-component/tests/components/async-streams-and-futures/module.wat
+++ b/crates/wit-component/tests/components/async-streams-and-futures/module.wat
@@ -1,6 +1,6 @@
 (module
-  (func (import "$root" "[async-lower]foo") (param i32 i32) (result i32))
-  (func (import "foo:foo/bar" "[async-lower]foo") (param i32 i32) (result i32))
+  (func (import "$root" "[async-lower]foo") (param i32 i32 i32) (result i32))
+  (func (import "foo:foo/bar" "[async-lower]foo") (param i32 i32 i32) (result i32))
   (func (import "$root" "[stream-new-2]foo") (result i64))
   (func (import "$root" "[stream-read-2]foo") (param i32 i32 i32) (result i32))
   (func (import "$root" "[stream-write-2]foo") (param i32 i32 i32) (result i32))
diff --git a/crates/wit-parser/src/abi.rs b/crates/wit-parser/src/abi.rs
index 9dc0920387..8c69db34d8 100644
--- a/crates/wit-parser/src/abi.rs
+++ b/crates/wit-parser/src/abi.rs
@@ -168,6 +168,7 @@ impl<'a> FlatTypes<'a> {
 
 impl Resolve {
     const MAX_FLAT_PARAMS: usize = 16;
+    const MAX_FLAT_ASYNC_PARAMS: usize = 4;
     const MAX_FLAT_RESULTS: usize = 1;
 
     /// Get the WebAssembly type signature for this interface function
@@ -175,15 +176,6 @@ impl Resolve {
     /// The first entry returned is the list of parameters and the second entry
     /// is the list of results for the wasm function signature.
     pub fn wasm_signature(&self, variant: AbiVariant, func: &Function) -> WasmSignature {
-        if let AbiVariant::GuestImportAsync = variant {
-            return WasmSignature {
-                params: vec![WasmType::Pointer; 2],
-                indirect_params: true,
-                results: vec![WasmType::I32],
-                retptr: true,
-            };
-        }
-
         // Note that one extra parameter is allocated in case a return pointer
         // is needed down below for imports.
         let mut storage = [WasmType::I32; Self::MAX_FLAT_PARAMS + 1];
@@ -191,7 +183,15 @@ impl Resolve {
         let ok = self.push_flat_list(func.params.iter().map(|(_, param)| param), &mut params);
         assert_eq!(ok, !params.overflow);
 
-        let indirect_params = !ok || params.cur > Self::MAX_FLAT_PARAMS;
+        let max = match variant {
+            AbiVariant::GuestImport
+            | AbiVariant::GuestExport
+            | AbiVariant::GuestExportAsync
+            | AbiVariant::GuestExportAsyncStackful => Self::MAX_FLAT_PARAMS,
+            AbiVariant::GuestImportAsync => Self::MAX_FLAT_ASYNC_PARAMS,
+        };
+
+        let indirect_params = !ok || params.cur > max;
         if indirect_params {
             params.types[0] = WasmType::Pointer;
             params.cur = 1;
@@ -216,48 +216,53 @@ impl Resolve {
             }
         }
 
-        match variant {
-            AbiVariant::GuestExportAsync => {
-                return WasmSignature {
-                    params: params.to_vec(),
-                    indirect_params,
-                    results: vec![WasmType::Pointer],
-                    retptr: false,
-                };
-            }
-            AbiVariant::GuestExportAsyncStackful => {
-                return WasmSignature {
-                    params: params.to_vec(),
-                    indirect_params,
-                    results: Vec::new(),
-                    retptr: false,
-                };
-            }
-            _ => {}
-        }
-
         let mut storage = [WasmType::I32; Self::MAX_FLAT_RESULTS];
         let mut results = FlatTypes::new(&mut storage);
-        if let Some(ty) = &func.result {
-            self.push_flat(ty, &mut results);
-        }
-
-        let retptr = results.overflow;
-
-        // Rust/C don't support multi-value well right now, so if a function
-        // would have multiple results then instead truncate it. Imports take a
-        // return pointer to write into and exports return a pointer they wrote
-        // into.
-        if retptr {
-            results.cur = 0;
-            match variant {
-                AbiVariant::GuestImport => {
-                    assert!(params.push(WasmType::Pointer));
+        let mut retptr = false;
+        match variant {
+            AbiVariant::GuestImport | AbiVariant::GuestExport => {
+                if let Some(ty) = &func.result {
+                    self.push_flat(ty, &mut results);
                 }
-                AbiVariant::GuestExport => {
-                    assert!(results.push(WasmType::Pointer));
+                retptr = results.overflow;
+
+                // Rust/C don't support multi-value well right now, so if a
+                // function would have multiple results then instead truncate
+                // it. Imports take a return pointer to write into and exports
+                // return a pointer they wrote into.
+                if retptr {
+                    results.cur = 0;
+                    match variant {
+                        AbiVariant::GuestImport => {
+                            assert!(params.push(WasmType::Pointer));
+                        }
+                        AbiVariant::GuestExport => {
+                            assert!(results.push(WasmType::Pointer));
+                        }
+                        _ => unreachable!(),
+                    }
+                }
+            }
+            AbiVariant::GuestImportAsync => {
+                // If this function has a result, a pointer must be passed to
+                // get filled in by the async runtime.
+                if func.result.is_some() {
+                    assert!(params.push(WasmType::Pointer));
+                    retptr = true;
                 }
-                _ => unreachable!(),
+
+                // The result of this function is a status code.
+                assert!(results.push(WasmType::I32));
+            }
+            AbiVariant::GuestExportAsync => {
+                // The result of this function is a status code. Note that the
+                // function results are entirely ignored here as they aren't
+                // part of the ABI and are handled in the `task.return`
+                // intrinsic.
+                assert!(results.push(WasmType::I32));
+            }
+            AbiVariant::GuestExportAsyncStackful => {
+                // No status code, and like async exports no result handling.
             }
         }
 
diff --git a/tests/cli/component-model-async/abi.wast b/tests/cli/component-model-async/abi.wast
new file mode 100644
index 0000000000..e684da4c94
--- /dev/null
+++ b/tests/cli/component-model-async/abi.wast
@@ -0,0 +1,172 @@
+;; RUN: wast --assert default --snapshot tests/snapshots % -f cm-async,cm-fixed-size-list,cm-async-stackful
+
+;; async lower
+(component
+  (core module $libc (memory (export "memory") 1))
+  (core instance $libc (instantiate $libc))
+
+  ;; func()
+  (import "f1" (func $f1))
+  (core func $f1 (canon lower (func $f1) async))
+  (core module $m1 (func (import "" "f") (result i32)))
+  (core instance (instantiate $m1 (with "" (instance (export "f" (func $f1))))))
+
+  ;; func(x: u32)
+  (import "f2" (func $f2 (param "x" u32)))
+  (core func $f2 (canon lower (func $f2) async))
+  (core module $m2 (func (import "" "f") (param i32) (result i32)))
+  (core instance (instantiate $m2 (with "" (instance (export "f" (func $f2))))))
+
+  ;; func() -> u32
+  (import "f3" (func $f3 (result u32)))
+  (core func $f3 (canon lower (func $f3) async (memory $libc "memory")))
+  (core module $m3 (func (import "" "f") (param i32) (result i32)))
+  (core instance (instantiate $m3 (with "" (instance (export "f" (func $f3))))))
+
+  ;; func(x: u32, y: f32, z: string)
+  (import "f4" (func $f4 (param "x" u32) (param "y" f32) (param "z" string)))
+  (core func $f4 (canon lower (func $f4) async (memory $libc "memory")))
+  (core module $m4 (func (import "" "f") (param i32 f32 i32 i32) (result i32)))
+  (core instance (instantiate $m4 (with "" (instance (export "f" (func $f4))))))
+
+  ;; func() -> f32
+  (import "f5" (func $f5 (result f32)))
+  (core func $f5 (canon lower (func $f5) async (memory $libc "memory")))
+  (core module $m5 (func (import "" "f") (param i32) (result i32)))
+  (core instance (instantiate $m5 (with "" (instance (export "f" (func $f5))))))
+
+  ;; func(x: list<string; 4>) -> f32
+  (import "f6" (func $f6 (param "x" (list string 6)) (result f32)))
+  (core func $f6 (canon lower (func $f6) async (memory $libc "memory")))
+  (core module $m6 (func (import "" "f") (param i32 i32) (result i32)))
+  (core instance (instantiate $m6 (with "" (instance (export "f" (func $f6))))))
+)
+
+;; async lift, callback abi
+(component
+  ;; func()
+  (core module $m1
+    (func (export "cb") (param i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (result i32) unreachable))
+  (core instance $m1 (instantiate $m1))
+  (func
+    (canon lift (core func $m1 "f") async (callback (func $m1 "cb"))))
+
+  ;; func(x: u32)
+  (core module $m2
+    (func (export "cb") (param i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (param i32) (result i32) unreachable))
+  (core instance $m2 (instantiate $m2))
+  (func (param "x" u32)
+    (canon lift (core func $m2 "f") async (callback (func $m2 "cb"))))
+
+  ;; func() -> u32
+  (core module $m3
+    (func (export "cb") (param i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (result i32) unreachable))
+  (core instance $m3 (instantiate $m3))
+  (func (result u32)
+    (canon lift (core func $m3 "f") async (callback (func $m3 "cb"))))
+
+  ;; func(x: f32)
+  (core module $m4
+    (func (export "cb") (param i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (param f32) (result i32) unreachable))
+  (core instance $m4 (instantiate $m4))
+  (func (param "x" f32)
+    (canon lift (core func $m4 "f") async (callback (func $m4 "cb"))))
+
+  ;; func(x: f32, y: string)
+  (core module $m5
+    (memory (export "memory") 1)
+    (func (export "cb") (param i32 i32 i32) (result i32) unreachable)
+    (func (export "realloc") (param i32 i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (param f32 i32 i32) (result i32) unreachable))
+  (core instance $m5 (instantiate $m5))
+  (func (param "x" f32) (param "y" string)
+    (canon lift (core func $m5 "f") async (callback (func $m5 "cb"))
+      (memory $m5 "memory") (realloc (func $m5 "realloc"))))
+
+  ;; func(x: list<string; 4>)
+  (core module $m6
+    (memory (export "memory") 1)
+    (func (export "cb") (param i32 i32 i32) (result i32) unreachable)
+    (func (export "realloc") (param i32 i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (param i32 i32 i32 i32 i32 i32 i32 i32) (result i32) unreachable))
+  (core instance $m6 (instantiate $m6))
+  (func (param "x" (list string 4))
+    (canon lift (core func $m6 "f") async (callback (func $m6 "cb"))
+      (memory $m6 "memory") (realloc (func $m6 "realloc"))))
+
+  ;; func(x: list<string; 10>)
+  (core module $m7
+    (memory (export "memory") 1)
+    (func (export "cb") (param i32 i32 i32) (result i32) unreachable)
+    (func (export "realloc") (param i32 i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (param i32) (result i32) unreachable))
+  (core instance $m7 (instantiate $m7))
+  (func (param "x" (list string 10))
+    (canon lift (core func $m7 "f") async (callback (func $m7 "cb"))
+      (memory $m7 "memory") (realloc (func $m7 "realloc"))))
+)
+
+;; async lift, stackful abi
+(component
+  ;; func()
+  (core module $m1
+    (func (export "f") unreachable))
+  (core instance $m1 (instantiate $m1))
+  (func
+    (canon lift (core func $m1 "f") async))
+
+  ;; func(x: u32)
+  (core module $m2
+    (func (export "f") (param i32) unreachable))
+  (core instance $m2 (instantiate $m2))
+  (func (param "x" u32)
+    (canon lift (core func $m2 "f") async))
+
+  ;; func() -> u32
+  (core module $m3
+    (func (export "f") unreachable))
+  (core instance $m3 (instantiate $m3))
+  (func (result u32)
+    (canon lift (core func $m3 "f") async))
+
+  ;; func(x: f32)
+  (core module $m4
+    (func (export "f") (param f32) unreachable))
+  (core instance $m4 (instantiate $m4))
+  (func (param "x" f32)
+    (canon lift (core func $m4 "f") async))
+
+  ;; func(x: f32, y: string)
+  (core module $m5
+    (memory (export "memory") 1)
+    (func (export "realloc") (param i32 i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (param f32 i32 i32) unreachable))
+  (core instance $m5 (instantiate $m5))
+  (func (param "x" f32) (param "y" string)
+    (canon lift (core func $m5 "f") async
+      (memory $m5 "memory") (realloc (func $m5 "realloc"))))
+
+  ;; func(x: list<string; 4>)
+  (core module $m6
+    (memory (export "memory") 1)
+    (func (export "realloc") (param i32 i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (param i32 i32 i32 i32 i32 i32 i32 i32) unreachable))
+  (core instance $m6 (instantiate $m6))
+  (func (param "x" (list string 4))
+    (canon lift (core func $m6 "f") async
+      (memory $m6 "memory") (realloc (func $m6 "realloc"))))
+
+  ;; func(x: list<string; 10>)
+  (core module $m7
+    (memory (export "memory") 1)
+    (func (export "realloc") (param i32 i32 i32 i32) (result i32) unreachable)
+    (func (export "f") (param i32) unreachable))
+  (core instance $m7 (instantiate $m7))
+  (func (param "x" (list string 10))
+    (canon lift (core func $m7 "f") async
+      (memory $m7 "memory") (realloc (func $m7 "realloc"))))
+)
diff --git a/tests/snapshots/cli/component-model-async/abi.wast.json b/tests/snapshots/cli/component-model-async/abi.wast.json
new file mode 100644
index 0000000000..b6a59dbeba
--- /dev/null
+++ b/tests/snapshots/cli/component-model-async/abi.wast.json
@@ -0,0 +1,23 @@
+{
+  "source_filename": "tests/cli/component-model-async/abi.wast",
+  "commands": [
+    {
+      "type": "module",
+      "line": 4,
+      "filename": "abi.0.wasm",
+      "module_type": "binary"
+    },
+    {
+      "type": "module",
+      "line": 46,
+      "filename": "abi.1.wasm",
+      "module_type": "binary"
+    },
+    {
+      "type": "module",
+      "line": 114,
+      "filename": "abi.2.wasm",
+      "module_type": "binary"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/tests/snapshots/cli/component-model-async/abi.wast/0.print b/tests/snapshots/cli/component-model-async/abi.wast/0.print
new file mode 100644
index 0000000000..1f2caa6b3e
--- /dev/null
+++ b/tests/snapshots/cli/component-model-async/abi.wast/0.print
@@ -0,0 +1,96 @@
+(component
+  (core module $libc (;0;)
+    (memory (;0;) 1)
+    (export "memory" (memory 0))
+  )
+  (core instance $libc (;0;) (instantiate $libc))
+  (type (;0;) (func))
+  (import "f1" (func $f1 (;0;) (type 0)))
+  (core func $f1 (;0;) (canon lower (func $f1) async))
+  (core module $m1 (;1;)
+    (type (;0;) (func (result i32)))
+    (import "" "f" (func (;0;) (type 0)))
+  )
+  (core instance (;1;)
+    (export "f" (func $f1))
+  )
+  (core instance (;2;) (instantiate $m1
+      (with "" (instance 1))
+    )
+  )
+  (type (;1;) (func (param "x" u32)))
+  (import "f2" (func $f2 (;1;) (type 1)))
+  (core func $f2 (;1;) (canon lower (func $f2) async))
+  (core module $m2 (;2;)
+    (type (;0;) (func (param i32) (result i32)))
+    (import "" "f" (func (;0;) (type 0)))
+  )
+  (core instance (;3;)
+    (export "f" (func $f2))
+  )
+  (core instance (;4;) (instantiate $m2
+      (with "" (instance 3))
+    )
+  )
+  (type (;2;) (func (result u32)))
+  (import "f3" (func $f3 (;2;) (type 2)))
+  (alias core export $libc "memory" (core memory (;0;)))
+  (core func $f3 (;2;) (canon lower (func $f3) async (memory 0)))
+  (core module $m3 (;3;)
+    (type (;0;) (func (param i32) (result i32)))
+    (import "" "f" (func (;0;) (type 0)))
+  )
+  (core instance (;5;)
+    (export "f" (func $f3))
+  )
+  (core instance (;6;) (instantiate $m3
+      (with "" (instance 5))
+    )
+  )
+  (type (;3;) (func (param "x" u32) (param "y" f32) (param "z" string)))
+  (import "f4" (func $f4 (;3;) (type 3)))
+  (alias core export $libc "memory" (core memory (;1;)))
+  (core func $f4 (;3;) (canon lower (func $f4) async (memory 1)))
+  (core module $m4 (;4;)
+    (type (;0;) (func (param i32 f32 i32 i32) (result i32)))
+    (import "" "f" (func (;0;) (type 0)))
+  )
+  (core instance (;7;)
+    (export "f" (func $f4))
+  )
+  (core instance (;8;) (instantiate $m4
+      (with "" (instance 7))
+    )
+  )
+  (type (;4;) (func (result f32)))
+  (import "f5" (func $f5 (;4;) (type 4)))
+  (alias core export $libc "memory" (core memory (;2;)))
+  (core func $f5 (;4;) (canon lower (func $f5) async (memory 2)))
+  (core module $m5 (;5;)
+    (type (;0;) (func (param i32) (result i32)))
+    (import "" "f" (func (;0;) (type 0)))
+  )
+  (core instance (;9;)
+    (export "f" (func $f5))
+  )
+  (core instance (;10;) (instantiate $m5
+      (with "" (instance 9))
+    )
+  )
+  (type (;5;) (list string 6))
+  (type (;6;) (func (param "x" 5) (result f32)))
+  (import "f6" (func $f6 (;5;) (type 6)))
+  (alias core export $libc "memory" (core memory (;3;)))
+  (core func $f6 (;5;) (canon lower (func $f6) async (memory 3)))
+  (core module $m6 (;6;)
+    (type (;0;) (func (param i32 i32) (result i32)))
+    (import "" "f" (func (;0;) (type 0)))
+  )
+  (core instance (;11;)
+    (export "f" (func $f6))
+  )
+  (core instance (;12;) (instantiate $m6
+      (with "" (instance 11))
+    )
+  )
+)
diff --git a/tests/snapshots/cli/component-model-async/abi.wast/1.print b/tests/snapshots/cli/component-model-async/abi.wast/1.print
new file mode 100644
index 0000000000..08815a75a2
--- /dev/null
+++ b/tests/snapshots/cli/component-model-async/abi.wast/1.print
@@ -0,0 +1,150 @@
+(component
+  (core module $m1 (;0;)
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
+    (type (;1;) (func (result i32)))
+    (export "cb" (func 0))
+    (export "f" (func 1))
+    (func (;0;) (type 0) (param i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (result i32)
+      unreachable
+    )
+  )
+  (core instance $m1 (;0;) (instantiate $m1))
+  (type (;0;) (func))
+  (alias core export $m1 "f" (core func (;0;)))
+  (alias core export $m1 "cb" (core func (;1;)))
+  (func (;0;) (type 0) (canon lift (core func 0) async (callback 1)))
+  (core module $m2 (;1;)
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
+    (type (;1;) (func (param i32) (result i32)))
+    (export "cb" (func 0))
+    (export "f" (func 1))
+    (func (;0;) (type 0) (param i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (param i32) (result i32)
+      unreachable
+    )
+  )
+  (core instance $m2 (;1;) (instantiate $m2))
+  (type (;1;) (func (param "x" u32)))
+  (alias core export $m2 "f" (core func (;2;)))
+  (alias core export $m2 "cb" (core func (;3;)))
+  (func (;1;) (type 1) (canon lift (core func 2) async (callback 3)))
+  (core module $m3 (;2;)
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
+    (type (;1;) (func (result i32)))
+    (export "cb" (func 0))
+    (export "f" (func 1))
+    (func (;0;) (type 0) (param i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (result i32)
+      unreachable
+    )
+  )
+  (core instance $m3 (;2;) (instantiate $m3))
+  (type (;2;) (func (result u32)))
+  (alias core export $m3 "f" (core func (;4;)))
+  (alias core export $m3 "cb" (core func (;5;)))
+  (func (;2;) (type 2) (canon lift (core func 4) async (callback 5)))
+  (core module $m4 (;3;)
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
+    (type (;1;) (func (param f32) (result i32)))
+    (export "cb" (func 0))
+    (export "f" (func 1))
+    (func (;0;) (type 0) (param i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (param f32) (result i32)
+      unreachable
+    )
+  )
+  (core instance $m4 (;3;) (instantiate $m4))
+  (type (;3;) (func (param "x" f32)))
+  (alias core export $m4 "f" (core func (;6;)))
+  (alias core export $m4 "cb" (core func (;7;)))
+  (func (;3;) (type 3) (canon lift (core func 6) async (callback 7)))
+  (core module $m5 (;4;)
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
+    (type (;1;) (func (param i32 i32 i32 i32) (result i32)))
+    (type (;2;) (func (param f32 i32 i32) (result i32)))
+    (memory (;0;) 1)
+    (export "memory" (memory 0))
+    (export "cb" (func 0))
+    (export "realloc" (func 1))
+    (export "f" (func 2))
+    (func (;0;) (type 0) (param i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (param i32 i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;2;) (type 2) (param f32 i32 i32) (result i32)
+      unreachable
+    )
+  )
+  (core instance $m5 (;4;) (instantiate $m5))
+  (type (;4;) (func (param "x" f32) (param "y" string)))
+  (alias core export $m5 "f" (core func (;8;)))
+  (alias core export $m5 "cb" (core func (;9;)))
+  (alias core export $m5 "memory" (core memory (;0;)))
+  (alias core export $m5 "realloc" (core func (;10;)))
+  (func (;4;) (type 4) (canon lift (core func 8) async (callback 9) (memory 0) (realloc 10)))
+  (core module $m6 (;5;)
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
+    (type (;1;) (func (param i32 i32 i32 i32) (result i32)))
+    (type (;2;) (func (param i32 i32 i32 i32 i32 i32 i32 i32) (result i32)))
+    (memory (;0;) 1)
+    (export "memory" (memory 0))
+    (export "cb" (func 0))
+    (export "realloc" (func 1))
+    (export "f" (func 2))
+    (func (;0;) (type 0) (param i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (param i32 i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;2;) (type 2) (param i32 i32 i32 i32 i32 i32 i32 i32) (result i32)
+      unreachable
+    )
+  )
+  (core instance $m6 (;5;) (instantiate $m6))
+  (type (;5;) (list string 4))
+  (type (;6;) (func (param "x" 5)))
+  (alias core export $m6 "f" (core func (;11;)))
+  (alias core export $m6 "cb" (core func (;12;)))
+  (alias core export $m6 "memory" (core memory (;1;)))
+  (alias core export $m6 "realloc" (core func (;13;)))
+  (func (;5;) (type 6) (canon lift (core func 11) async (callback 12) (memory 1) (realloc 13)))
+  (core module $m7 (;6;)
+    (type (;0;) (func (param i32 i32 i32) (result i32)))
+    (type (;1;) (func (param i32 i32 i32 i32) (result i32)))
+    (type (;2;) (func (param i32) (result i32)))
+    (memory (;0;) 1)
+    (export "memory" (memory 0))
+    (export "cb" (func 0))
+    (export "realloc" (func 1))
+    (export "f" (func 2))
+    (func (;0;) (type 0) (param i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (param i32 i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;2;) (type 2) (param i32) (result i32)
+      unreachable
+    )
+  )
+  (core instance $m7 (;6;) (instantiate $m7))
+  (type (;7;) (list string 10))
+  (type (;8;) (func (param "x" 7)))
+  (alias core export $m7 "f" (core func (;14;)))
+  (alias core export $m7 "cb" (core func (;15;)))
+  (alias core export $m7 "memory" (core memory (;2;)))
+  (alias core export $m7 "realloc" (core func (;16;)))
+  (func (;6;) (type 8) (canon lift (core func 14) async (callback 15) (memory 2) (realloc 16)))
+)
diff --git a/tests/snapshots/cli/component-model-async/abi.wast/2.print b/tests/snapshots/cli/component-model-async/abi.wast/2.print
new file mode 100644
index 0000000000..83f4c93847
--- /dev/null
+++ b/tests/snapshots/cli/component-model-async/abi.wast/2.print
@@ -0,0 +1,108 @@
+(component
+  (core module $m1 (;0;)
+    (type (;0;) (func))
+    (export "f" (func 0))
+    (func (;0;) (type 0)
+      unreachable
+    )
+  )
+  (core instance $m1 (;0;) (instantiate $m1))
+  (type (;0;) (func))
+  (alias core export $m1 "f" (core func (;0;)))
+  (func (;0;) (type 0) (canon lift (core func 0) async))
+  (core module $m2 (;1;)
+    (type (;0;) (func (param i32)))
+    (export "f" (func 0))
+    (func (;0;) (type 0) (param i32)
+      unreachable
+    )
+  )
+  (core instance $m2 (;1;) (instantiate $m2))
+  (type (;1;) (func (param "x" u32)))
+  (alias core export $m2 "f" (core func (;1;)))
+  (func (;1;) (type 1) (canon lift (core func 1) async))
+  (core module $m3 (;2;)
+    (type (;0;) (func))
+    (export "f" (func 0))
+    (func (;0;) (type 0)
+      unreachable
+    )
+  )
+  (core instance $m3 (;2;) (instantiate $m3))
+  (type (;2;) (func (result u32)))
+  (alias core export $m3 "f" (core func (;2;)))
+  (func (;2;) (type 2) (canon lift (core func 2) async))
+  (core module $m4 (;3;)
+    (type (;0;) (func (param f32)))
+    (export "f" (func 0))
+    (func (;0;) (type 0) (param f32)
+      unreachable
+    )
+  )
+  (core instance $m4 (;3;) (instantiate $m4))
+  (type (;3;) (func (param "x" f32)))
+  (alias core export $m4 "f" (core func (;3;)))
+  (func (;3;) (type 3) (canon lift (core func 3) async))
+  (core module $m5 (;4;)
+    (type (;0;) (func (param i32 i32 i32 i32) (result i32)))
+    (type (;1;) (func (param f32 i32 i32)))
+    (memory (;0;) 1)
+    (export "memory" (memory 0))
+    (export "realloc" (func 0))
+    (export "f" (func 1))
+    (func (;0;) (type 0) (param i32 i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (param f32 i32 i32)
+      unreachable
+    )
+  )
+  (core instance $m5 (;4;) (instantiate $m5))
+  (type (;4;) (func (param "x" f32) (param "y" string)))
+  (alias core export $m5 "f" (core func (;4;)))
+  (alias core export $m5 "memory" (core memory (;0;)))
+  (alias core export $m5 "realloc" (core func (;5;)))
+  (func (;4;) (type 4) (canon lift (core func 4) async (memory 0) (realloc 5)))
+  (core module $m6 (;5;)
+    (type (;0;) (func (param i32 i32 i32 i32) (result i32)))
+    (type (;1;) (func (param i32 i32 i32 i32 i32 i32 i32 i32)))
+    (memory (;0;) 1)
+    (export "memory" (memory 0))
+    (export "realloc" (func 0))
+    (export "f" (func 1))
+    (func (;0;) (type 0) (param i32 i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (param i32 i32 i32 i32 i32 i32 i32 i32)
+      unreachable
+    )
+  )
+  (core instance $m6 (;5;) (instantiate $m6))
+  (type (;5;) (list string 4))
+  (type (;6;) (func (param "x" 5)))
+  (alias core export $m6 "f" (core func (;6;)))
+  (alias core export $m6 "memory" (core memory (;1;)))
+  (alias core export $m6 "realloc" (core func (;7;)))
+  (func (;5;) (type 6) (canon lift (core func 6) async (memory 1) (realloc 7)))
+  (core module $m7 (;6;)
+    (type (;0;) (func (param i32 i32 i32 i32) (result i32)))
+    (type (;1;) (func (param i32)))
+    (memory (;0;) 1)
+    (export "memory" (memory 0))
+    (export "realloc" (func 0))
+    (export "f" (func 1))
+    (func (;0;) (type 0) (param i32 i32 i32 i32) (result i32)
+      unreachable
+    )
+    (func (;1;) (type 1) (param i32)
+      unreachable
+    )
+  )
+  (core instance $m7 (;6;) (instantiate $m7))
+  (type (;7;) (list string 10))
+  (type (;8;) (func (param "x" 7)))
+  (alias core export $m7 "f" (core func (;8;)))
+  (alias core export $m7 "memory" (core memory (;2;)))
+  (alias core export $m7 "realloc" (core func (;9;)))
+  (func (;6;) (type 8) (canon lift (core func 8) async (memory 2) (realloc 9)))
+)