diff --git a/ChangeLog b/ChangeLog
index a4e7b7dc29..e8c0fc5fbb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jul 19 12:33:29 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* array.c (rb_ary_clear): should not unshare embedded array, and
+	  should make unshared array embedded.
+
 Mon Jul 19 09:00:58 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* NEWS (Kernel#instance_eval): add an incompatible change since
diff --git a/array.c b/array.c
index 4cb0cb7731..c2a4e8563e 100644
--- a/array.c
+++ b/array.c
@@ -2775,7 +2775,10 @@ rb_ary_clear(VALUE ary)
     rb_ary_modify_check(ary);
     ARY_SET_LEN(ary, 0);
     if (ARY_SHARED_P(ary)) {
-	rb_ary_unshare(ary);
+	if (!ARY_EMBED_P(ary)) {
+	    rb_ary_unshare(ary);
+	    FL_SET_EMBED(ary);
+	}
     }
     else if (ARY_DEFAULT_SIZE * 2 < ARY_CAPA(ary)) {
 	ary_resize_capa(ary, ARY_DEFAULT_SIZE * 2);