diff --git a/Fwk/AppFwk/cafVizExtensions/cafCategoryMapper.cpp b/Fwk/AppFwk/cafVizExtensions/cafCategoryMapper.cpp
index d2539edb21..45d1e89dd0 100644
--- a/Fwk/AppFwk/cafVizExtensions/cafCategoryMapper.cpp
+++ b/Fwk/AppFwk/cafVizExtensions/cafCategoryMapper.cpp
@@ -5,6 +5,7 @@
 #include "cvfMath.h"
 #include "cvfOverlayColorLegend.h"
 #include "cvfTextureImage.h"
+#include <cmath>
 
 using namespace cvf;