diff --git a/wit/async/async.go b/wit/async/async.go
index 710fd37..8bda86a 100644
--- a/wit/async/async.go
+++ b/wit/async/async.go
@@ -218,22 +218,29 @@ func Yield() {
 }
 
 //go:wasmimport $root [waitable-set-new]
+//go:noescape
 func waitableSetNew() uint32
 
 //go:wasmimport $root [waitable-set-poll]
+//go:noescape
 func waitableSetPoll(waitableSet uint32, eventPayload unsafe.Pointer) uint32
 
 //go:wasmimport $root [waitable-set-drop]
+//go:noescape
 func waitableSetDrop(waitableSet uint32)
 
 //go:wasmimport $root [waitable-join]
+//go:noescape
 func waitableJoin(waitable, waitableSet uint32)
 
 //go:wasmimport $root [context-get-0]
+//go:noescape
 func contextGet() unsafe.Pointer
 
 //go:wasmimport $root [context-set-0]
+//go:noescape
 func contextSet(value unsafe.Pointer)
 
 //go:wasmimport $root [subtask-drop]
+//go:noescape
 func subtaskDrop(subtask uint32)
diff --git a/wit/async/empty.s b/wit/async/empty.s
new file mode 100644
index 0000000..5444f20
--- /dev/null
+++ b/wit/async/empty.s
@@ -0,0 +1,3 @@
+// This file exists for testing this package without WebAssembly,
+// allowing empty function bodies with a //go:wasmimport directive.
+// See https://pkg.go.dev/cmd/compile for more information.