--- a/js/src/jsapi-tests/testExternalStrings.cpp
+++ b/js/src/jsapi-tests/testExternalStrings.cpp
@@ -21,17 +21,17 @@ static void
 finalize_str(const JSStringFinalizer* fin, char16_t* chars);
 
 static const JSStringFinalizer finalizer1 = { finalize_str };
 static const JSStringFinalizer finalizer2 = { finalize_str };
 
 static void
 finalize_str(const JSStringFinalizer* fin, char16_t* chars)
 {
-    if (chars && ArrayEqual(const_cast<const char16_t*>(chars), arr, arrlen)) {
+    if (chars && ArrayEqual(chars, arr, arrlen)) {
         if (fin == &finalizer1) {
             ++finalized1;
         } else if (fin == &finalizer2) {
             ++finalized2;
         }
     }
 }