diff --git a/src/osgPlugins/hdr/hdrwriter.cpp b/src/osgPlugins/hdr/hdrwriter.cpp
index 14fa04e5b..25432b553 100644
--- a/src/osgPlugins/hdr/hdrwriter.cpp
+++ b/src/osgPlugins/hdr/hdrwriter.cpp
@@ -25,6 +25,7 @@
  
 */
 
+#include <stdlib.h>
 
 #include "hdrwriter.h"
 
diff --git a/src/osgViewer/ViewerBase.cpp b/src/osgViewer/ViewerBase.cpp
index e8402bd1d..bc7dbdf24 100644
--- a/src/osgViewer/ViewerBase.cpp
+++ b/src/osgViewer/ViewerBase.cpp
@@ -11,6 +11,9 @@
  * OpenSceneGraph Public License for more details.
 */
 
+#include <stdlib.h>
+#include <string.h>
+
 #include <osgViewer/ViewerBase>
 #include <osgViewer/Renderer>