diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index bf29f948b77..d8a3c2f7484 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -6898,6 +6898,9 @@ void WasmBinaryBuilder::visitRefAs(RefAs* curr, uint8_t code) {
       WASM_UNREACHABLE("invalid code for ref.as_*");
   }
   curr->value = popNonVoidExpression();
+  if (!curr->value->type.isRef() && curr->value->type != Type::unreachable) {
+    throwError("bad input type for ref.as: " + curr->value->type.toString());
+  }
   curr->finalize();
 }
 
diff --git a/test/lit/binary/bad-ref-as.test b/test/lit/binary/bad-ref-as.test
new file mode 100644
index 00000000000..2afa1990478
--- /dev/null
+++ b/test/lit/binary/bad-ref-as.test
@@ -0,0 +1,6 @@
+;; Test that we error properly on a file with a ref.as of a non-ref type.
+
+;; RUN: not wasm-opt %s.wasm 2>&1 | filecheck %s
+
+;; CHECK: parse exception: bad input type for ref.as: i32
+
diff --git a/test/lit/binary/bad-ref-as.test.wasm b/test/lit/binary/bad-ref-as.test.wasm
new file mode 100644
index 00000000000..637537dd22e
Binary files /dev/null and b/test/lit/binary/bad-ref-as.test.wasm differ