diff --git a/src/OpenGl/OpenGl_GraphicDriver_Layer.cxx b/src/OpenGl/OpenGl_GraphicDriver_Layer.cxx
index efa084e2af..291bbfa6a0 100755
--- a/src/OpenGl/OpenGl_GraphicDriver_Layer.cxx
+++ b/src/OpenGl/OpenGl_GraphicDriver_Layer.cxx
@@ -13,6 +13,8 @@
 #include <OpenGl_AspectText.hxx>
 #include <OpenGl_TextParam.hxx>
 
+#include <GL/glu.h>
+
 /*----------------------------------------------------------------------*/
 
 struct OpenGl_LAYER_PROP
diff --git a/src/OpenGl/OpenGl_telem_util.cxx b/src/OpenGl/OpenGl_telem_util.cxx
index e6756735f0..42ae2858b4 100755
--- a/src/OpenGl/OpenGl_telem_util.cxx
+++ b/src/OpenGl/OpenGl_telem_util.cxx
@@ -48,6 +48,8 @@ when a face has confused or aligned points.
 
 ************************************************************************/
 
+#include <stdio.h>
+
 #include <OpenGl_GlCore11.hxx>
 
 #include <OpenGl_telem_util.hxx>