diff --git a/ChangeLog b/ChangeLog
index f1f62449bc..318e2549ca 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Feb 11 11:47:41 2009  Tanaka Akira  <akr@fsij.org>
+
+	* ext/socket/ipsocket.c (Init_ipsocket): undef getpeereid at IPSocket.
+
 Wed Feb 11 10:16:34 2009  Tanaka Akira  <akr@fsij.org>
 
 	* ext/socket/extconf.rb: check getpeereid.
diff --git a/ext/socket/ipsocket.c b/ext/socket/ipsocket.c
index fe687907b7..21d9739b75 100644
--- a/ext/socket/ipsocket.c
+++ b/ext/socket/ipsocket.c
@@ -243,4 +243,6 @@ Init_ipsocket(void)
     rb_define_method(rb_cIPSocket, "peeraddr", ip_peeraddr, 0);
     rb_define_method(rb_cIPSocket, "recvfrom", ip_recvfrom, -1);
     rb_define_singleton_method(rb_cIPSocket, "getaddress", ip_s_getaddress, 1);
+    rb_undef_method(rb_cIPSocket, "getpeereid");
+
 }