diff --git a/glxbackend.cpp b/glxbackend.cpp
index 4325f8ed5e..65f257d7af 100644
--- a/glxbackend.cpp
+++ b/glxbackend.cpp
@@ -43,7 +43,7 @@ GlxBackend::GlxBackend()
     , window(None)
     , fbconfig(NULL)
     , glxWindow(None)
-    , ctx(None)
+    , ctx(nullptr)
     , haveSwapInterval(false)
 {
     init();