diff --git a/src/pam/afs_util.c b/src/pam/afs_util.c
index 67a9fd3538..8725487666 100644
--- a/src/pam/afs_util.c
+++ b/src/pam/afs_util.c
@@ -166,7 +166,7 @@ out:
 /* get the current AFS pag for the calling process */
 static afs_int32 curpag()
 {
-   gid_t groups[30];
+   gid_t groups[NGROUPS_MAX];
    afs_uint32 g0, g1;
    afs_uint32 h, l, ret;
       
diff --git a/src/sys/pagsh.c b/src/sys/pagsh.c
index 581d925e8b..de09c0e474 100644
--- a/src/sys/pagsh.c
+++ b/src/sys/pagsh.c
@@ -84,11 +84,11 @@ char **argv;
 
 static afs_uint32 curpag()
 {
-    afs_uint32 groups[30];
+    afs_uint32 groups[NGROUPS_MAX];
     afs_uint32 g0, g1;
     afs_uint32 h, l, ret;
 
-    if (getgroups(30, groups) < 2) return 0;
+    if (getgroups(sizeof groups/sizeof groups[0], groups) < 2) return 0;
 
     g0 = groups[0] & 0xffff;
     g1 = groups[1] & 0xffff;