diff --git a/libs/main/core/piobject.cpp b/libs/main/core/piobject.cpp
index b9aa1c26..1f2bfc64 100644
--- a/libs/main/core/piobject.cpp
+++ b/libs/main/core/piobject.cpp
@@ -660,7 +660,11 @@ PIObject::Connection::Connection() {
 
 bool PIObject::Connection::disconnect() {
 	if (!isValid() || !src_o) return false;
+	if (!src_o->isPIObject()) return false;
 	bool ndm = dest_o && (src_o != dest_o), ret = false, found = false;
+	if (dest_o) {
+		if (!dest_o->isPIObject()) ndm = false;
+	}
 	PIMutexLocker _ml(src_o->mutex_connect);
 	if (ndm) dest_o->mutex_connect.lock();
 	for (int i = 0; i < src_o->connections.size_s(); ++i) {
@@ -680,8 +684,10 @@ bool PIObject::Connection::disconnect() {
 			break;
 		}
 	}
-	if (dest_o)
-		dest_o->updateConnectors();
+	if (dest_o) {
+		if (dest_o->isPIObject())
+			dest_o->updateConnectors();
+	}
 	if (ndm) dest_o->mutex_connect.unlock();
 	return ret;
 }