diff --git a/lib/gssapi/mech/gss_authorize_localname.c b/lib/gssapi/mech/gss_authorize_localname.c
index f8a9848b5..e87934a9e 100644
--- a/lib/gssapi/mech/gss_authorize_localname.c
+++ b/lib/gssapi/mech/gss_authorize_localname.c
@@ -33,7 +33,7 @@
 #include "mech_locl.h"
 
 static gss_buffer_desc localLoginUserAttr = {
-    sizeof("local-login-user"),
+    sizeof("local-login-user") - 1,
     "local-login-user"
 };