--- a/js/xpconnect/src/XPCWrappedNative.cpp
+++ b/js/xpconnect/src/XPCWrappedNative.cpp
@@ -2215,10 +2215,9 @@         else if (count == 2 && array[0] == isupp) {
             name = JS_sprintf_append(name, "%s", array[1]->GetNameString());
         } else {
             for (uint16_t i = 0; i < count; i++) {
-                const char* fmt = (i == 0) ?
-                                    "(%s" : (i == count-1) ?
-                                        ", %s)" : ", %s";
-                name = JS_sprintf_append(name, fmt,
+                name = JS_sprintf_append(name, (i == 0) ?
+                                         "(%s" : (i == count-1) ?
+                                         ", %s)" : ", %s",
                                          array[i]->GetNameString());
             }
         }