diff --git a/capa/rules/__init__.py b/capa/rules/__init__.py
index 89517950..49742bf4 100644
--- a/capa/rules/__init__.py
+++ b/capa/rules/__init__.py
@@ -123,7 +123,7 @@ class Flavor:
 
     def __eq__(self, scope) -> bool:
         # Flavors aren't supposed to be compared directly.
-        assert isinstance(scope, Scope)
+        assert isinstance(scope, Scope) or isinstance(scope, str)
         return (scope == self.static) or (scope == self.dynamic)