diff --git a/common/JackEngine.cpp b/common/JackEngine.cpp
index 788124d2..95eb548c 100644
--- a/common/JackEngine.cpp
+++ b/common/JackEngine.cpp
@@ -604,7 +604,7 @@ int JackEngine::ClientExternalOpen(const char* name, int pid, int uuid, int* ref
         EnsureUUID(uuid);
     }
 
-    jack_log("JackEngine::ClientExternalOpen: uuid = %d, name = %s ", uuid, real_name);
+    jack_log("JackEngine::ClientExternalOpen: uuid = %d, name = %s", uuid, real_name);
 
     int refnum = AllocateRefnum();
     if (refnum < 0) {
@@ -895,7 +895,7 @@ int JackEngine::CheckPortsConnect(int refnum, jack_port_id_t src, jack_port_id_t
     JackPort* src_port = fGraphManager->GetPort(src);
     JackPort* dst_port = fGraphManager->GetPort(dst);
 
-    jack_log("CheckPortsConnect(caller = %d, src = %d, dst = %d)", refnum, src_port->GetRefNum(), dst_port->GetRefNum());
+    jack_log("JackEngine::CheckPortsConnect(ref = %d, src = %d, dst = %d)", refnum, src_port->GetRefNum(), dst_port->GetRefNum());
 
     int src_self = src_port->GetRefNum() == refnum ? 1 : 0;
     int dst_self = dst_port->GetRefNum() == refnum ? 1 : 0;
@@ -956,7 +956,7 @@ int JackEngine::CheckPortsConnect(int refnum, jack_port_id_t src, jack_port_id_t
 
 int JackEngine::PortConnect(int refnum, const char* src, const char* dst)
 {
-    jack_log("JackEngine::PortConnect src = %s dst = %s", src, dst);
+    jack_log("JackEngine::PortConnect ref = %d src = %s dst = %s", refnum, src, dst);
     jack_port_id_t port_src, port_dst;
 
     return (fGraphManager->GetTwoPorts(src, dst, &port_src, &port_dst) < 0)
@@ -966,7 +966,7 @@ int JackEngine::PortConnect(int refnum, const char* src, const char* dst)
 
 int JackEngine::PortConnect(int refnum, jack_port_id_t src, jack_port_id_t dst)
 {
-    jack_log("JackEngine::PortConnect src = %d dst = %d", src, dst);
+    jack_log("JackEngine::PortConnect ref = %d src = %d dst = %d", refnum, src, dst);
     JackClientInterface* client;
     int ref;
 
@@ -1008,7 +1008,7 @@ int JackEngine::PortConnect(int refnum, jack_port_id_t src, jack_port_id_t dst)
 
 int JackEngine::PortDisconnect(int refnum, const char* src, const char* dst)
 {
-    jack_log("JackEngine::PortDisconnect src = %s dst = %s", src, dst);
+    jack_log("JackEngine::PortDisconnect ref = %d src = %s dst = %s", refnum, src, dst);
     jack_port_id_t port_src, port_dst;
 
     return (fGraphManager->GetTwoPorts(src, dst, &port_src, &port_dst) < 0)
@@ -1018,7 +1018,7 @@ int JackEngine::PortDisconnect(int refnum, const char* src, const char* dst)
 
 int JackEngine::PortDisconnect(int refnum, jack_port_id_t src, jack_port_id_t dst)
 {
-    jack_log("JackEngine::PortDisconnect src = %d dst = %d", src, dst);
+    jack_log("JackEngine::PortDisconnect ref = %d src = %d dst = %d", refnum, src, dst);
 
     if (dst == ALL_PORTS) {
 
diff --git a/common/JackLockedEngine.h b/common/JackLockedEngine.h
index c662916d..d0e67412 100644
--- a/common/JackLockedEngine.h
+++ b/common/JackLockedEngine.h
@@ -88,7 +88,11 @@ class SERVER_EXPORT JackLockedEngine
         {}
         ~JackLockedEngine()
         {}
-
+        
+        bool Lock() { return fEngine.Lock(); }
+        bool Unlock() { return fEngine.Unlock(); }
+        bool Trylock() { return fEngine.Trylock(); }
+  
         int Open()
         {
             // No lock needed
diff --git a/macosx/coremidi/JackCoreMidiDriver.cpp b/macosx/coremidi/JackCoreMidiDriver.cpp
index 753a7675..45d41d29 100644
--- a/macosx/coremidi/JackCoreMidiDriver.cpp
+++ b/macosx/coremidi/JackCoreMidiDriver.cpp
@@ -519,17 +519,25 @@ JackCoreMidiDriver::CloseAux()
 void
 JackCoreMidiDriver::Restart()
 {
+    // Lock between this thread and RT thread
     JackLock lock(this);
-    // Use first alias
-    SaveConnections(1);
-    Stop();
-    Detach();
-    CloseAux();
-    OpenAux();
-    Attach();
-    Start();
-    // Use first alias and partial port naming
-    LoadConnections(1, false);
+    
+    // Lock between this thread and request thread
+    if (fEngine->Lock()) {
+        // Use first alias
+        SaveConnections(1);
+        Stop();
+        Detach();
+        CloseAux();
+        OpenAux();
+        Attach();
+        Start();
+        // Use first alias and partial port naming
+        LoadConnections(1, false);
+        fEngine->Unlock();
+    } else {
+        jack_error("Cannot acquire engine lock...");
+    }
 }
 
 void