diff --git a/testing/test_pluginmanager.py b/testing/test_pluginmanager.py
index 0fead87f..67ea6789 100644
--- a/testing/test_pluginmanager.py
+++ b/testing/test_pluginmanager.py
@@ -126,6 +126,8 @@ class A:
 
 def test_register_skips_properties(he_pm: PluginManager) -> None:
     class ClassWithProperties:
+        property_was_executed: bool = False
+
         @property
         def some_func(self):
             self.property_was_executed = True