diff --git a/ChangeLog b/ChangeLog
index 8757e8bce7..79cd853eea 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Aug 25 17:56:40 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* array.c (rb_ary_sample): use frozen shared array to get rid of
+	  reallocation.
+
 Wed Aug 25 03:42:43 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* ext/dl/cfunc.c (rb_dlcfunc_call): workaround for VC9 for x64.
diff --git a/array.c b/array.c
index 172a653aa2..b506b086d4 100644
--- a/array.c
+++ b/array.c
@@ -3826,6 +3826,7 @@ rb_ary_sample(int argc, VALUE *argv, VALUE ary)
     rb_scan_args(argc, argv, "1", &nv);
     n = NUM2LONG(nv);
     if (n < 0) rb_raise(rb_eArgError, "negative sample number");
+    RB_GC_GUARD(ary) = ary_make_shared(ary);
     ptr = RARRAY_PTR(ary);
     len = RARRAY_LEN(ary);
     if (n > len) n = len;
@@ -3872,7 +3873,6 @@ rb_ary_sample(int argc, VALUE *argv, VALUE ary)
 	VALUE *ptr_result;
 	result = rb_ary_new4(len, ptr);
 	ptr_result = RARRAY_PTR(result);
-	RB_GC_GUARD(ary);
 	for (i=0; i<n; i++) {
 	    j = RAND_UPTO(len-i) + i;
 	    nv = ptr_result[j];