1 files changed, 7 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/parser/bug1657557.js b/js/src/jit-test/tests/parser/bug1657557.js
new file mode 100644
index 0000000000..6035035166
--- /dev/null
+++ b/js/src/jit-test/tests/parser/bug1657557.js
@@ -0,0 +1,7 @@
+setImmutablePrototype(Function.__proto__);
+
+if (helperThreadCount() > 0) {
+    offThreadCompileToStencil("function f() {}");
+    var stencil = finishOffThreadStencil();
+    evalStencil(stencil);
+}