diff --git a/crypto/heimdal/kcm/connect.c b/crypto/heimdal/kcm/connect.c
index b3a21aa66a0b..edad6fcdf259 100644
--- a/crypto/heimdal/kcm/connect.c
+++ b/crypto/heimdal/kcm/connect.c
@@ -149,7 +149,7 @@ update_client_creds(int s, kcm_client *peer)
 	struct sockcred *sc;
 	
 	memset(&msg, 0, sizeof(msg));
-	crmsgsize = CMSG_SPACE(SOCKCREDSIZE(NGROUPS));
+	crmsgsize = CMSG_SPACE(SOCKCREDSIZE(CMGROUP_MAX));
 	if (crmsgsize == 0)
 	    return 1 ;