diff --git a/src/common/QskMetaFunction.cpp b/src/common/QskMetaFunction.cpp
index 56d04080..9b3bea0d 100644
--- a/src/common/QskMetaFunction.cpp
+++ b/src/common/QskMetaFunction.cpp
@@ -204,14 +204,18 @@ void QskMetaFunction::invoke( QObject* object,
                 return;
             }
 
+#if QT_CONFIG(thread)
             QSemaphore semaphore;
+#endif
 
             auto event = new QMetaCallEvent(
                 m_functionCall, nullptr, 0, argv, &semaphore );
 
             QCoreApplication::postEvent( receiver, event );
 
+#if QT_CONFIG(thread)
             semaphore.acquire();
+#endif
 
             break;
         }
diff --git a/src/common/QskMetaInvokable.cpp b/src/common/QskMetaInvokable.cpp
index 1f73633d..64c118f0 100644
--- a/src/common/QskMetaInvokable.cpp
+++ b/src/common/QskMetaInvokable.cpp
@@ -192,14 +192,18 @@ static void qskInvokeMetaCall(
                 return;
             }
 
+#if QT_CONFIG(thread)
             QSemaphore semaphore;
+#endif
 
             auto event = new MetaCallEvent( call, metaObject,
                 offset, index, args, &semaphore );
 
             QCoreApplication::postEvent( receiver, event );
 
+#if QT_CONFIG(thread)
             semaphore.acquire();
+#endif
 
             break;
         }