@@ -, +, @@ 
---
 inc/InterfaceGraphic_X11.hxx                  | 1 +
 samples/qt/Common/src/View.cxx                | 1 +
 src/InterfaceGraphic/InterfaceGraphic_X11.hxx | 1 +
 src/OpenGl/OpenGl_Context.cxx                 | 1 +
 src/OpenGl/OpenGl_Workspace_Raytrace.cxx      | 1 +
 src/Xw/Xw_Window.cxx                          | 1 +
 6 files changed, 6 insertions(+)
--- a/inc/InterfaceGraphic_X11.hxx	
+++ a/inc/InterfaceGraphic_X11.hxx	
@@ -21,6 +21,7 @@ 
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/Xatom.h>
+#define GLX_GLXEXT_LEGACY
 #include <GL/glx.h>
 
 #if defined (sun) || defined (SUNOS) || defined (__alpha) || defined (DECOSF1) || defined (sgi) || defined (IRIX) || defined (__hpux)|| defined (HPUX)
--- a/samples/qt/Common/src/View.cxx	
+++ a/samples/qt/Common/src/View.cxx	
@@ -28,6 +28,7 @@ 
 #include <Cocoa_Window.hxx>
 #else
 #include <QX11Info>
+#define GLX_GLXEXT_LEGACY
 #include <GL/glx.h>
 #include <X11/Xutil.h>
 #include <X11/Xatom.h>
--- a/src/InterfaceGraphic/InterfaceGraphic_X11.hxx	
+++ a/src/InterfaceGraphic/InterfaceGraphic_X11.hxx	
@@ -21,6 +21,7 @@ 
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/Xatom.h>
+#define GLX_GLXEXT_LEGACY
 #include <GL/glx.h>
 
 #if defined (sun) || defined (SUNOS) || defined (__alpha) || defined (DECOSF1) || defined (sgi) || defined (IRIX) || defined (__hpux)|| defined (HPUX)
--- a/src/OpenGl/OpenGl_Context.cxx	
+++ a/src/OpenGl/OpenGl_Context.cxx	
@@ -39,6 +39,7 @@ 
 #elif defined(__APPLE__) && !defined(MACOSX_USE_GLX)
   #include <dlfcn.h>
 #else
+  #define GLX_GLXEXT_LEGACY
   #include <GL/glx.h> // glXGetProcAddress()
 #endif
 
--- a/src/OpenGl/OpenGl_Workspace_Raytrace.cxx	
+++ a/src/OpenGl/OpenGl_Workspace_Raytrace.cxx	
@@ -32,6 +32,7 @@ 
 #elif defined(__APPLE__) && !defined(MACOSX_USE_GLX)
   #include <OpenGL/CGLCurrent.h>
 #else
+  #define GLX_GLXEXT_LEGACY
   #include <GL/glx.h>
 #endif
 
--- a/src/Xw/Xw_Window.cxx	
+++ a/src/Xw/Xw_Window.cxx	
@@ -20,6 +20,7 @@ 
 #include <Aspect_Convert.hxx>
 #include <Aspect_WindowDefinitionError.hxx>
 
+#define GLX_GLXEXT_LEGACY
 #include <GL/glx.h>
 
 namespace
--