--- a/python/mozbuild/mozbuild/configure/__init__.py
+++ b/python/mozbuild/mozbuild/configure/__init__.py
@@ -473,8 +473,8 @@
             msg = 'Unknown option: %s' % without_value
             if self._help:
                 self._logger.warning(msg)
-            else:
-                raise InvalidOptionError(msg)
+            #else:
+            #    raise InvalidOptionError(msg)

         # Run the execution queue
         for func, args in self._execution_queue: