diff --git a/ChangeLog b/ChangeLog
index 511f00f6..65360d73 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2009-02-08  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
+
+	Don't send ip parameter to a tracker if ip parameter is empty
+	string.	
+	* src/DefaultBtAnnounce.cc
+
 2009-02-07  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
 
 	Adjusted line feed.
diff --git a/src/DefaultBtAnnounce.cc b/src/DefaultBtAnnounce.cc
index 1a05d2e0..05ea4cef 100644
--- a/src/DefaultBtAnnounce.cc
+++ b/src/DefaultBtAnnounce.cc
@@ -167,7 +167,7 @@ std::string DefaultBtAnnounce::getAnnounceUrl() {
   } else {
     url += "&supportcrypto=1";
   }
-  if(option->defined(PREF_BT_EXTERNAL_IP)) {
+  if(!option->blank(PREF_BT_EXTERNAL_IP)) {
     url += "&ip="+option->get(PREF_BT_EXTERNAL_IP);
   }
   return url;