diff --git a/include/osg/GL2Extensions b/include/osg/GL2Extensions
index 1e23e775e..9a696ea51 100644
--- a/include/osg/GL2Extensions
+++ b/include/osg/GL2Extensions
@@ -21,6 +21,8 @@
 #include <osg/Referenced>
 #include <osg/GL>
 
+#include <string>
+
 namespace osg {
 
 class OSG_EXPORT GL2Extensions : public osg::Referenced
diff --git a/include/osg/Shader b/include/osg/Shader
index e79207dd7..f15e4e481 100644
--- a/include/osg/Shader
+++ b/include/osg/Shader
@@ -24,7 +24,6 @@
 #include <osg/buffered_value>
 
 #include <set>
-#include <string>
 
 namespace osg {