diff --git a/include/osg/ColorMask b/include/osg/ColorMask
index f44013409..f508983c0 100644
--- a/include/osg/ColorMask
+++ b/include/osg/ColorMask
@@ -5,6 +5,7 @@
 #ifndef OSG_COLORMASK
 #define OSG_COLORMASK 1
 
+#include <osg/Export>
 #include <osg/StateAttribute>
 #include <osg/StateSet>
 #include <osg/Types>