diff --git a/js2py/internals/opcodes.py b/js2py/internals/opcodes.py
index 15c57ccd..2f6c65f5 100644
--- a/js2py/internals/opcodes.py
+++ b/js2py/internals/opcodes.py
@@ -798,7 +798,7 @@ def eval(self, ctx):
 g = ''
 for g in globals():
     try:
-        if not issubclass(globals()[g], OP_CODE) or g is 'OP_CODE':
+        if not issubclass(globals()[g], OP_CODE) or g == 'OP_CODE':
             continue
     except:
         continue