diff --git a/gunicorn/glogging.py b/gunicorn/glogging.py
index d8241449..018e7eca 100644
--- a/gunicorn/glogging.py
+++ b/gunicorn/glogging.py
@@ -4,6 +4,7 @@
 # See the NOTICE for more information.
 
 import base64
+import binascii
 import time
 import logging
 logging.Logger.manager.emittedNoHandlerWarning = 1
@@ -394,6 +395,9 @@ class Logger(object):
                 except TypeError as exc:
                     self.debug("Couldn't get username: %s", exc)
                     return user
+                except binascii.Error as exc:
+                    self.debug("Couldn't get username: %s", exc)
+                    return user
                 if len(auth) == 2:
                     user = auth[0]
         return user