diff --git a/ChangeLog b/ChangeLog
index bdac453bfc..6422e89e5d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Tue Mar  2 15:54:40 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* regcomp.c (noname_disable_map): add NT_ANCHOR case.
+	  Without this change, captured groups in anchors (look-ahead,
+	  look-behind, and so on) are not removed and
+	  unintended invalid backref error occur. [ruby-core:28235]
+
+	* regcomp.c (renumber_by_map): ditto.
+
 Tue Mar  2 14:42:00 2010  Kenta Murata <mrkn@mrkn.jp>
 
 	* test/dl/test_closure.rb: forget to revert at r26764.
@@ -17,7 +26,8 @@ Mon Mar  1 23:26:56 2010  Tanaka Akira  <akr@fsij.org>
 
 Mon Mar  1 20:07:06 2010  TAKANO Mitsuhiro (takano32)  <tak@no32.tk>
 
-	* ext/zlib/zlib.c (zstream_expand_buffer_into): remove compare different type values warning.
+	* ext/zlib/zlib.c (zstream_expand_buffer_into): remove compare
+	  different type values warning.
 
 Mon Mar  1 17:42:45 2010  wanabe  <s.wanabe@gmail.com>
 
diff --git a/regcomp.c b/regcomp.c
index 57c02626ae..b681e669bf 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -1794,6 +1794,20 @@ noname_disable_map(Node** plink, GroupNumRemap* map, int* counter)
     }
     break;
 
+  case NT_ANCHOR:
+    {
+      AnchorNode* an = NANCHOR(node);
+      switch (an->type) {
+      case ANCHOR_PREC_READ:
+      case ANCHOR_PREC_READ_NOT:
+      case ANCHOR_LOOK_BEHIND:
+      case ANCHOR_LOOK_BEHIND_NOT:
+	r = noname_disable_map(&(an->target), map, counter);
+	break;
+      }
+    }
+    break;
+
   default:
     break;
   }
@@ -1852,6 +1866,20 @@ renumber_by_map(Node* node, GroupNumRemap* map)
     r = renumber_node_backref(node, map);
     break;
 
+  case NT_ANCHOR:
+    {
+      AnchorNode* an = NANCHOR(node);
+      switch (an->type) {
+      case ANCHOR_PREC_READ:
+      case ANCHOR_PREC_READ_NOT:
+      case ANCHOR_LOOK_BEHIND:
+      case ANCHOR_LOOK_BEHIND_NOT:
+	r = renumber_by_map(an->target, map);
+	break;
+      }
+    }
+    break;
+
   default:
     break;
   }