--- PDL-2.4.3/Graphics/TriD/OpenGL/opengl.pd.gl	2006-06-22 00:51:43.000000000 -0600
+++ PDL-2.4.3/Graphics/TriD/OpenGL/opengl.pd	2008-01-29 09:30:50.000000000 -0700
@@ -348,6 +348,7 @@
 	 $com .= " $_" if(1 || /-D/);
   }
   $com .= " -D_LANGUAGE_C -DAPIENTRY=''";  # forces prototypes of SGI GL 
+  $com .= " -DGLvoid=void";  # workaround for RHEL5 MESA
 
   print STDERR "*** CPP command: $com $nfile |\n";