diff --git a/miplearn/components/cuts.py b/miplearn/components/cuts.py
index 92f4a55..7743fd1 100644
--- a/miplearn/components/cuts.py
+++ b/miplearn/components/cuts.py
@@ -48,6 +48,8 @@ class UserCutsComponent(Component):
         self.classifiers = {}
         violation_to_instance_idx = {}
         for (idx, instance) in enumerate(training_instances):
+            if not hasattr(instance, "found_violated_user_cuts"):
+                continue
             for v in instance.found_violated_user_cuts:
                 if v not in self.classifiers:
                     self.classifiers[v] = deepcopy(self.classifier_prototype)