diff --git a/decompiler/util/insertion_ordered_set.py b/decompiler/util/insertion_ordered_set.py
index 32d18aabc..ab380b0a2 100644
--- a/decompiler/util/insertion_ordered_set.py
+++ b/decompiler/util/insertion_ordered_set.py
@@ -60,6 +60,9 @@ def __repr__(self):
     def __str__(self):
         return "{%s}" % (", ".join(map(repr, self.keys())))
 
+    def __or__(self, other: AbstractSet[Any]) -> InsertionOrderedSet:
+        return InsertionOrderedSet(super().__or__(other))
+ 
     difference = property(lambda self: self.__sub__)
     difference_update = property(lambda self: self.__isub__)
     intersection = property(lambda self: self.__and__)