diff --git a/ChangeLog b/ChangeLog
index c973fe42..83e0f86f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -26,6 +26,7 @@ Nedko Arnaudov
 	* Correct jack_internal_client_load for wrapper layer.
 	* In thread model, execute a dummy cycle to be sure thread has the correct properties (ensure thread creation is finished).
 	* Correct jack_port_get_connections function (should return NULL when no connections).
+	* Start client RT thread only if a thread routine or callback has been setup with jack_set_process_callback or jack_set_process_thread.
 
 2008-03-10 Stephane Letz  <letz@grame.fr>
 		
diff --git a/common/JackClient.cpp b/common/JackClient.cpp
index 81543945..b2b7b6c6 100644
--- a/common/JackClient.cpp
+++ b/common/JackClient.cpp
@@ -250,8 +250,9 @@ int JackClient::Activate()
     #endif
     */
 
-    if (StartThread() < 0)
-        return -1;
+	if (fProcess || fThreadFun) 
+		if (StartThread() < 0)
+			return -1;
 
     int result = -1;
     fChannel->ClientActivate(GetClientControl()->fRefNum, &result);
@@ -292,7 +293,8 @@ int JackClient::Deactivate()
     	fThread->Kill();
     #endif
     */
-    fThread->Kill();
+	if (fProcess || fThreadFun) 
+		fThread->Kill();
     return result;
 }