diff --git a/servers/ext2/protect.c b/servers/ext2/protect.c
index 9fdfe50a5..0fe5d2e9a 100644
--- a/servers/ext2/protect.c
+++ b/servers/ext2/protect.c
@@ -130,7 +130,7 @@ PRIVATE int in_group(gid_t grp)
 {
   int i;
 
-  if (credentials.vu_ngroups >= NGROUPS_MAX)
+  if (credentials.vu_ngroups > NGROUPS_MAX)
 	return(EINVAL);
 
   for (i = 0; i < credentials.vu_ngroups; i++)
diff --git a/servers/mfs/protect.c b/servers/mfs/protect.c
index 0a6d01afb..6ca64d860 100644
--- a/servers/mfs/protect.c
+++ b/servers/mfs/protect.c
@@ -124,7 +124,7 @@ PRIVATE int in_group(gid_t grp)
 {
   int i;
 
-  if (credentials.vu_ngroups >= NGROUPS_MAX)
+  if (credentials.vu_ngroups > NGROUPS_MAX)
 	return(EINVAL);
 
   for (i = 0; i < credentials.vu_ngroups; i++)