diff --git a/crates/backend/src/codegen.rs b/crates/backend/src/codegen.rs
index c8decb4a136..8ae6b738c00 100644
--- a/crates/backend/src/codegen.rs
+++ b/crates/backend/src/codegen.rs
@@ -806,6 +806,16 @@ impl TryToTokens for ast::Export {
                     add_check(quote! {
                         let _: #wasm_bindgen::__rt::marker::CheckSupportsConstructor<#class>;
                     });
+
+                    if self.function.r#async {
+                        (quote_spanned! {
+                            self.function.name_span =>
+                            #[deprecated(note = "async constructors are not supported")]
+                            fn constructor() {}
+                            constructor();
+                        })
+                        .to_tokens(into);
+                    }
                 }
                 ast::MethodKind::Operation(operation) => match operation.kind {
                     ast::OperationKind::Getter(_) | ast::OperationKind::Setter(_) => {
diff --git a/crates/macro-support/src/parser.rs b/crates/macro-support/src/parser.rs
index a10d823b3b3..46c76a1ef21 100644
--- a/crates/macro-support/src/parser.rs
+++ b/crates/macro-support/src/parser.rs
@@ -1418,11 +1418,6 @@ impl MacroParse<&ClassMarker> for &mut syn::ImplItemFn {
             FunctionPosition::Impl { self_ty: class },
         )?;
         let method_kind = if opts.constructor().is_some() {
-            if function.r#async {
-                self.attrs.push(syn::parse_quote! {
-                    #[deprecated(note = "constructors cannot be async")]
-                });
-            }
             ast::MethodKind::Constructor
         } else {
             let is_static = method_self.is_none();