diff --git a/vyper/semantics/namespace.py b/vyper/semantics/namespace.py
index 3d065f25a9..e22c1c417c 100644
--- a/vyper/semantics/namespace.py
+++ b/vyper/semantics/namespace.py
@@ -86,6 +86,7 @@ def update(self, other):
 
     def clear(self):
         super().clear()
+        self._constants.clear()
         self.__init__()
 
     def validate_assignment(self, attr):