diff --git a/TypeNodes.py b/TypeNodes.py
index 85d32ee14c4176b520934e3fab373fb9a3e17d92..2967c2d27f45b40d77247075d18d19b5fa0fb294 100644
--- a/TypeNodes.py
+++ b/TypeNodes.py
@@ -25,9 +25,9 @@ class ClassInterNode(ASTNode):
         if self.superInter:
             unique = []
             for inter in self.superInter:
-                if inter.name in unique:
-                    raise Exception("ERROR: Class/Interface '{}' implements duplicate interfaces '{}'".format(self.name, inter.name))
-                unique.append(inter.name)
+                if inter.canonName in unique:
+                    raise Exception("ERROR: Class/Interface '{}' implements duplicate interfaces '{}'".format(self.name, inter.canonName))
+                unique.append(inter.canonName)
 
         # 7. A class or interface must not declare two methods with the same signature (name and parameter types).
         # 9. A class/interface must not contain two methods with the same signature but different return types