1 files changed, 1 insertions, 1 deletions
diff --git a/array.c b/array.c
index 2e9d927f6a..acc59d20b4 100644
--- a/array.c
+++ b/array.c
@@ -502,7 +502,7 @@ rb_ary_shift(ary)
     if (RARRAY(ary)->len == 0) return Qnil;
     top = RARRAY(ary)->ptr[0];
     if (RARRAY_LEN(ary) < ARY_DEFAULT_SIZE && !FL_TEST(ary, ELTS_SHARED)) {
-	MEMMOVE(RARRAY_PTR(ary), RARRAY_PTR(ary)+1, VALUE, RARRAY_LEN(ary));
+	MEMMOVE(RARRAY_PTR(ary), RARRAY_PTR(ary)+1, VALUE, RARRAY_LEN(ary)-1);
     }
     else {
 	if (!FL_TEST(ary, ELTS_SHARED)) {