diff --git a/common/JackEngine.cpp b/common/JackEngine.cpp
index 65382e78..6093adf6 100644
--- a/common/JackEngine.cpp
+++ b/common/JackEngine.cpp
@@ -736,6 +736,35 @@ int JackEngine::PortUnRegister(int refnum, jack_port_id_t port_index)
     }
 }
 
+// this check is to prevent apps to self connect to other apps
+// TODO: make this work with multiple clients per app
+int JackEngine::CheckPortsConnect(int refnum, jack_port_id_t src, jack_port_id_t dst)
+{
+    JackPort* src_port = fGraphManager->GetPort(src);
+    JackPort* dst_port = fGraphManager->GetPort(dst);
+
+    jack_info("CheckPortsConnect(caller = %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;
+
+    jack_info("src_self is %s", src_self ? "true" : "false");
+    jack_info("dst_self is %s", dst_self ? "true" : "false");
+
+    // 0 means client is connecting other client ports (i.e. control app patchbay functionality)
+    // 1 means client is connecting its own port to port of other client (i.e. self hooking into system app)
+    // 2 means client is connecting its own ports (i.e. for app internal functionality)
+    // TODO: Make this check an engine option and more tweakable (return error or success)
+    // MAYBE: make the engine option changable on the fly and expose it through client or control API
+    if (src_self + dst_self != 0)
+    {
+        jack_info("ignoring port self connect request");
+        return 0;
+    }
+
+    return 1;
+}
+
 int JackEngine::PortConnect(int refnum, const char* src, const char* dst)
 {
     jack_log("JackEngine::PortConnect src = %s dst = %s", src, dst);
@@ -776,7 +805,12 @@ int JackEngine::PortConnect(int refnum, jack_port_id_t src, jack_port_id_t dst)
         return -1;
     }
 
-    int res = fGraphManager->Connect(src, dst);
+    int res = CheckPortsConnect(refnum, src, dst);
+    if (res != 1) {
+        return res;
+    }
+
+    res = fGraphManager->Connect(src, dst);
     if (res == 0)
         NotifyPortConnect(src, dst, true);
     return res;
@@ -820,15 +854,21 @@ int JackEngine::PortDisconnect(int refnum, jack_port_id_t src, jack_port_id_t ds
         }
 
         return ret;
-    } else if (fGraphManager->CheckPorts(src, dst) < 0) {
-        return -1;
-    } else if (fGraphManager->Disconnect(src, dst) == 0) {
-        // Notifications
-        NotifyPortConnect(src, dst, false);
-        return 0;
-    } else {
+    }
+
+    if (fGraphManager->CheckPorts(src, dst) < 0) {
         return -1;
     }
+
+    int res = CheckPortsConnect(refnum, src, dst);
+    if (res != 1) {
+        return res;
+    }
+
+    res = fGraphManager->Disconnect(src, dst);
+    if (res == 0)
+        NotifyPortConnect(src, dst, false);
+    return res;
 }
 
 int JackEngine::PortRename(int refnum, jack_port_id_t port, const char* name)
diff --git a/common/JackEngine.h b/common/JackEngine.h
index 9ec65124..9f689378 100644
--- a/common/JackEngine.h
+++ b/common/JackEngine.h
@@ -71,6 +71,8 @@ class SERVER_EXPORT JackEngine
         void NotifyPortRename(jack_port_id_t src);
         void NotifyActivate(int refnum);
 
+        int CheckPortsConnect(int refnum, jack_port_id_t src, jack_port_id_t dst);
+
     public:
 
         JackEngine(JackGraphManager* manager, JackSynchro* table, JackEngineControl* controler);