diff --git a/ChangeLog b/ChangeLog
index 30cab8267c..c0905e83f6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed May 21 16:48:22 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* array.c (rb_ary_compact_bang): avoid forceful realloc.
+
 Wed May 21 07:42:28 2008  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* string.c (rb_usascii_str_new): use rb_str_new.
diff --git a/array.c b/array.c
index 6fd7a75e01..f42eb9f826 100644
--- a/array.c
+++ b/array.c
@@ -2710,11 +2710,13 @@ rb_ary_compact_bang(VALUE ary)
 	if (NIL_P(*t)) t++;
 	else *p++ = *t++;
     }
-    if (RARRAY_LEN(ary) == (p - RARRAY_PTR(ary))) {
+    n = p - RARRAY_PTR(ary);
+    if (RARRAY_LEN(ary) == n) {
 	return Qnil;
     }
-    n = p - RARRAY_PTR(ary);
-    RESIZE_CAPA(ary, n);
+    if (n * 2 < ARY_CAPA(ary) && ARY_DEFAULT_SIZE * 2 < ARY_CAPA(ary)) {
+	RESIZE_CAPA(ary, ARY_DEFAULT_SIZE * 2);
+    }
     RARRAY(ary)->len = n;
 
     return ary;