diff --git a/tools/generate_input_to_stdnames_update.py b/tools/generate_input_to_stdnames_update.py
index 0b2107df..541ad514 100644
--- a/tools/generate_input_to_stdnames_update.py
+++ b/tools/generate_input_to_stdnames_update.py
@@ -7,7 +7,7 @@
 
 def parse_csv(csv_filepath):
     datamap = defaultdict(set)
-    pattern = re.compile("\w+")
+    pattern = re.compile(r"\w+")
     print(f"Opening {csv_filepath}")
     with open(csv_filepath, encoding='ascii') as csvfile:
         csvdata = csv.reader(csvfile)