diff --git a/src/Contexts/GlxContext.cpp b/src/Contexts/GlxContext.cpp
index 328edffd7..8d36d6f8a 100644
--- a/src/Contexts/GlxContext.cpp
+++ b/src/Contexts/GlxContext.cpp
@@ -18,6 +18,8 @@
 #include <GL/glxext.h>
 #include <Utility/Debug.h>
 
+#define None 0L // redef Xlib nonsense
+
 namespace Magnum { namespace Contexts {
 
 VisualID GlxContext::getVisualId(Display* nativeDisplay) {
diff --git a/src/Contexts/GlxContext.h b/src/Contexts/GlxContext.h
index 4f5cc775b..5612b3831 100644
--- a/src/Contexts/GlxContext.h
+++ b/src/Contexts/GlxContext.h
@@ -21,6 +21,9 @@
 
 #include "Magnum.h"
 #include <GL/glx.h>
+/* undef Xlib nonsense to avoid conflicts */
+#undef None
+#undef Always
 
 #include "AbstractContext.h"