diff --git a/uncompyle6/parsers/parse38.py b/uncompyle6/parsers/parse38.py
index 0aee3fa1..4ecb5e59 100644
--- a/uncompyle6/parsers/parse38.py
+++ b/uncompyle6/parsers/parse38.py
@@ -417,7 +417,7 @@ class Python38Parser(Python37Parser):
             [opname[: opname.rfind("_")] for opname in self.seen_ops]
         )
 
-        custom_ops_processed = set(["DICT_MERGE"])
+        custom_ops_processed = {"DICT_MERGE"}
 
         # Loop over instructions adding custom grammar rules based on
         # a specific instruction seen.