1 files changed, 1 insertions, 1 deletions
diff --git a/process.c b/process.c
index 67c4d3816b..9541c600d3 100644
--- a/process.c
+++ b/process.c
@@ -2464,7 +2464,7 @@ proc_setgroups(VALUE obj, VALUE ary)
 
     groups = ALLOCA_N(gid_t, ngroups);
 
-    for (i = 0; i < ngroups; i++) {
+    for (i = 0; i < ngroups && i < RARRAY(ary)->len; i++) {
         VALUE g = RARRAY(ary)->ptr[i];
 
 	if (FIXNUM_P(g)) {