diff --git a/imap/httpd.c b/imap/httpd.c

index 5dcf38dc4..d2fdeb945 100644

--- a/imap/httpd.c

+++ b/imap/httpd.c

@@ -1729,6 +1729,25 @@ static int examine_request(struct transaction_t *txn)

         txn->auth_chal.scheme = NULL;

     }

+    /* Drop auth credentials, if not a backend in a Murder */

+    else if (!config_mupdate_server || !config_getstring(IMAPOPT_PROXYSERVERS)) {

+        syslog(LOG_DEBUG, "drop auth creds");

+

+        free(httpd_userid);

+        httpd_userid = NULL;

+

+        free(httpd_extrafolder);

+        httpd_extrafolder = NULL;

+

+        free(httpd_extradomain);

+        httpd_extradomain = NULL;

+

+        if (httpd_authstate) {

+            auth_freestate(httpd_authstate);

+            httpd_authstate = NULL;

+        }

+    }

+

     /* Perform proxy authorization, if necessary */

     else if (saslprops.authid &&

              (hdr = spool_getheader(txn->req_hdrs, "Authorize-As")) &&