diff --git a/compiler/rustc_mir_transform/src/instsimplify.rs b/compiler/rustc_mir_transform/src/instsimplify.rs
index 87104364da6af..9ffa3358ac995 100644
--- a/compiler/rustc_mir_transform/src/instsimplify.rs
+++ b/compiler/rustc_mir_transform/src/instsimplify.rs
@@ -390,7 +390,9 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
         let body_abi = match body_ty.kind() {
             ty::FnDef(..) => body_ty.fn_sig(self.tcx).abi(),
             ty::Closure(..) => ExternAbi::RustCall,
+            ty::CoroutineClosure(..) => ExternAbi::RustCall,
             ty::Coroutine(..) => ExternAbi::Rust,
+            ty::Error(_) => return,
             _ => bug!("unexpected body ty: {body_ty:?}"),
         };
 
diff --git a/tests/ui/async-await/async-closures/instsimplify-nounwind.rs b/tests/ui/async-await/async-closures/instsimplify-nounwind.rs
new file mode 100644
index 0000000000000..344e5b367f926
--- /dev/null
+++ b/tests/ui/async-await/async-closures/instsimplify-nounwind.rs
@@ -0,0 +1,20 @@
+// Regression test for #477: simplify_nounwind_call missing CoroutineClosure arm.
+// Before the fix, the MIR instsimplify pass would ICE (bug!("unexpected body ty"))
+// when encountering an async closure body type during nounwind simplification.
+
+//@ edition:2021
+//@ build-pass
+
+async fn call_once(f: impl std::future::Future<Output = ()>) {
+    f.await;
+}
+
+fn main() {
+    let _ = async {
+        let x = 1i32;
+        let c = async move || {
+            let _ = x;
+        };
+        call_once(c()).await;
+    };
+}