diff --git a/titles/cxb/index.py b/titles/cxb/index.py
index 513b813..a4e7085 100644
--- a/titles/cxb/index.py
+++ b/titles/cxb/index.py
@@ -155,7 +155,7 @@ class CxbServlet(BaseServlet):
             filename = filetype_split[len(filetype_split) - 1]
 
             match = re.match(
-                "^([A-Za-z]*)(\d\d\d\d)$", filetype_split[len(filetype_split) - 1]
+                r"^([A-Za-z]*)(\d\d\d\d)$", filetype_split[len(filetype_split) - 1]
             )
             if match:
                 func_to_find += f"{inflection.underscore(match.group(1))}xxxx"