diff --git a/src/common/idle.c b/src/common/idle.c
index 808f7ad05..68c174fe9 100644
--- a/src/common/idle.c
+++ b/src/common/idle.c
@@ -61,7 +61,7 @@ static PyObject * idle_getIdleSec(PyObject *self, PyObject *args)
 #endif
 
 #ifndef _WIN32
-	if (!XScreenSaverQueryExtension(display, &event_base, &error_base))
+	if (XScreenSaverQueryExtension(display, &event_base, &error_base))
 	{
 		if (mit_info == NULL)
 			mit_info = XScreenSaverAllocInfo();