diff --git a/pyop2/codegen/loopycompat.py b/pyop2/codegen/loopycompat.py
index f3a3315b2..02493944e 100644
--- a/pyop2/codegen/loopycompat.py
+++ b/pyop2/codegen/loopycompat.py
@@ -32,6 +32,7 @@ class DimChanger(IdentityMapper):
     def __init__(self, callee_arg_dict, desired_shape):
         self.callee_arg_dict = callee_arg_dict
         self.desired_shape = desired_shape
+        super().__init__()
 
     def map_subscript(self, expr):
         if expr.aggregate.name not in self.callee_arg_dict:
@@ -130,6 +131,7 @@ def _shape_1_if_empty(shape_caller, shape_callee):
 class _FunctionCalledChecker(CombineMapper):
     def __init__(self, func_name):
         self.func_name = func_name
+        super().__init__()
 
     def combine(self, values):
         return any(values)