diff --git a/grudge/symbolic/operators.py b/grudge/symbolic/operators.py
index 2f8642fa71fa52756642969cb98912206abfacce..eece5cbff188cd57feff66e6bcd795d02a6e9add 100644
--- a/grudge/symbolic/operators.py
+++ b/grudge/symbolic/operators.py
@@ -104,7 +104,7 @@ class InterpolationOperator(Operator):
             raise ValueError("Interpolating from {} to {}"
             " does not do anything.".format(official_dd_in, official_dd_out))
 
-        super().__init__(dd_in, dd_out)
+        super(InterpolationOperator, self).__init__(dd_in, dd_out)
     mapper_method = intern("map_interpolation")