diff --git a/ChangeLog b/ChangeLog
index 0e9ea789..11d5547c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-08-28  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
+
+	Changed signature of util::executeHook().
+	* src/RequestGroupMan.cc
+	* src/util.cc
+	* src/util.h
+
 2010-08-28  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
 
 	Wait data arrives at clientSocket_ in
diff --git a/src/RequestGroupMan.cc b/src/RequestGroupMan.cc
index a1a8f6a4..4bf4b08f 100644
--- a/src/RequestGroupMan.cc
+++ b/src/RequestGroupMan.cc
@@ -255,12 +255,15 @@ static void executeStopHook
 {
   if(result->result == downloadresultcode::FINISHED &&
      !option->blank(PREF_ON_DOWNLOAD_COMPLETE)) {
-    util::executeHook(option->get(PREF_ON_DOWNLOAD_COMPLETE), result->gid);
+    util::executeHook(option->get(PREF_ON_DOWNLOAD_COMPLETE),
+                      util::itos(result->gid));
   } else if(result->result != downloadresultcode::IN_PROGRESS &&
             !option->blank(PREF_ON_DOWNLOAD_ERROR)) {
-    util::executeHook(option->get(PREF_ON_DOWNLOAD_ERROR), result->gid);
+    util::executeHook(option->get(PREF_ON_DOWNLOAD_ERROR),
+                      util::itos(result->gid));
   } else if(!option->blank(PREF_ON_DOWNLOAD_STOP)) {
-    util::executeHook(option->get(PREF_ON_DOWNLOAD_STOP), result->gid);
+    util::executeHook(option->get(PREF_ON_DOWNLOAD_STOP),
+                      util::itos(result->gid));
   }
 }
 
diff --git a/src/util.cc b/src/util.cc
index 9c12c6a3..6a0944e4 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -1346,17 +1346,17 @@ void removeMetalinkContentTypes(const SharedHandle<RequestGroup>& group)
   }
 }
 
-void executeHook(const std::string& command, gid_t gid)
+void executeHook(const std::string& command, const std::string& arg)
 {
   LogFactory::getInstance()->info("Executing user command: %s %s",
-                                  command.c_str(), util::itos(gid).c_str());
+                                  command.c_str(), arg.c_str());
 #ifndef __MINGW32__
   pid_t cpid = fork();
   if(cpid == -1) {
     LogFactory::getInstance()->error("fork() failed."
                                      " Cannot execute user command.");
   } else if(cpid == 0) {
-    execl(command.c_str(), command.c_str(), util::itos(gid).c_str(),
+    execl(command.c_str(), command.c_str(), arg.c_str(),
           reinterpret_cast<char*>(0));
     perror(("Could not execute user command: "+command).c_str());
     exit(EXIT_FAILURE);
@@ -1371,7 +1371,7 @@ void executeHook(const std::string& command, gid_t gid)
   memset(&pi, 0, sizeof (pi));
 
   std::string cmdline = command;
-  strappend(cmdline, " ", util::itos(gid));
+  strappend(cmdline, " ", arg);
 
   DWORD rc = CreateProcess(
                            NULL,
@@ -1402,7 +1402,7 @@ void executeHookByOptName
 (const RequestGroup* group, const Option* option, const std::string& opt)
 {
   if(!option->blank(opt)) {
-    executeHook(option->get(opt), group->getGID());
+    executeHook(option->get(opt), util::itos(group->getGID()));
   }
 }
 
diff --git a/src/util.h b/src/util.h
index 1cbfa546..af241569 100644
--- a/src/util.h
+++ b/src/util.h
@@ -396,7 +396,7 @@ bool inSameCidrBlock(const std::string& ip1, const std::string& ip2, int bits);
 
 void removeMetalinkContentTypes(const SharedHandle<RequestGroup>& group);
 
-void executeHook(const std::string& command, gid_t gid);
+void executeHook(const std::string& command, const std::string& arg);
 
 void executeHookByOptName
 (const SharedHandle<RequestGroup>& group, const Option* option,