diff --git a/uproot_methods/profiles/__init__.py b/uproot_methods/profiles/__init__.py
index e7dcb39..681e1eb 100644
--- a/uproot_methods/profiles/__init__.py
+++ b/uproot_methods/profiles/__init__.py
@@ -6,7 +6,7 @@
 import re
 
 def transformer(name):
-    m = re.match("^([a-zA-Z_][a-zA-Z_0-9]*)(\.[a-zA-Z_][a-zA-Z_0-9]*)*$", name)
+    m = re.match(r"^([a-zA-Z_][a-zA-Z_0-9]*)(\.[a-zA-Z_][a-zA-Z_0-9]*)*$", name)
     if m is None:
         raise ValueError("profile name must match \"identifier(.identifier)*\"")
     return getattr(importlib.import_module("uproot_methods.profiles." + m.string), "transform")