diff --git a/SyntopiaCore/GLEngine/Raytracer/AtomicCounter.h b/SyntopiaCore/GLEngine/Raytracer/AtomicCounter.h
index dc42d4a..c779c5e 100644
--- a/SyntopiaCore/GLEngine/Raytracer/AtomicCounter.h
+++ b/SyntopiaCore/GLEngine/Raytracer/AtomicCounter.h
@@ -3,6 +3,8 @@
 #include <QMutex>
 #include <QWaitCondition>
 
+#include <limits.h>
+
 namespace SyntopiaCore {
 	namespace GLEngine {