diff --git a/src/cherrypy/lib/httpauth.py b/src/cherrypy/lib/httpauth.py
index ea8448d339..a49b4b5385 100644
--- a/src/cherrypy/lib/httpauth.py
+++ b/src/cherrypy/lib/httpauth.py
@@ -225,7 +225,7 @@ def _A1(params, password):
     algorithm = params.get ("algorithm", MD5)
     H = DIGEST_AUTH_ENCODERS[algorithm]
 
-    if algorithm == MD5:
+    if algorithm in (MD5, 'md5'):
         # If the "algorithm" directive's value is "MD5" or is
         # unspecified, then A1 is:
         # A1 = unq(username-value) ":" unq(realm-value) ":" passwd