diff --git a/cpython/patches/0008-Make-Emscripten-trampolines-work-with-JSPI.patch b/cpython/patches/0008-Make-Emscripten-trampolines-work-with-JSPI.patch
index 6ed0d32977a..d2ed9627c70 100644
--- a/cpython/patches/0008-Make-Emscripten-trampolines-work-with-JSPI.patch
+++ b/cpython/patches/0008-Make-Emscripten-trampolines-work-with-JSPI.patch
@@ -270,7 +270,7 @@ index 0000000000..d2d24a6e0a
 +  if (n !== undefined) {
 +    return n;
 +  }
-+  n = WebAssembly.Function.type(wasmTable.get(func)).parameters.length;
++  n = wasmFunctionType(wasmTable.get(func)).parameters.length;
 +  _PyEM_CountFuncParams.cache.set(func, n);
 +  return n;
 +}
diff --git a/src/core/pre.js b/src/core/pre.js
index a77d78a3cb8..e57eabfa833 100644
--- a/src/core/pre.js
+++ b/src/core/pre.js
@@ -99,3 +99,13 @@ Module.iterObject = function* (object) {
     }
   }
 };
+
+function wasmFunctionType(wasm_func) {
+  if (!WebAssembly.Function) {
+    throw new Error("No type reflection");
+  }
+  if (WebAssembly.Function.type) {
+    return WebAssembly.Function.type(wasm_func);
+  }
+  return wasm_func.type();
+}
diff --git a/src/core/stack_switching/suspenders.mjs b/src/core/stack_switching/suspenders.mjs
index 758ce9c9778..cd66a4b10a7 100644
--- a/src/core/stack_switching/suspenders.mjs
+++ b/src/core/stack_switching/suspenders.mjs
@@ -154,7 +154,7 @@ export function createPromising(wasm_func) {
   if (promisingFunctionMap.has(wasm_func)) {
     return promisingFunctionMap.get(wasm_func);
   }
-  const type = WebAssembly.Function.type(wasm_func);
+  const type = wasmFunctionType(wasm_func);
   const module = getPromisingModule(type);
   const instance = new WebAssembly.Instance(module, {
     e: { i: wasm_func, s: suspenderGlobal },