diff --git a/js/src/jit-test/tests/ctypes/function-definition.js b/js/src/jit-test/tests/ctypes/function-definition.js
index 4df317a09..5882ba889 100644
--- a/js/src/jit-test/tests/ctypes/function-definition.js
+++ b/js/src/jit-test/tests/ctypes/function-definition.js
@@ -27,7 +27,7 @@ function test() {
 
   let lib;
   try {
-    lib = ctypes.open(ctypes.libraryName("c"));
+    lib = ctypes.open(ctypes.libraryName("m"));
   } catch (e) {
   }
   if (!lib)