diff --git a/Extras/GPUphysics/GPU_physics_demo.cxx b/Extras/GPUphysics/GPU_physics_demo.cpp
similarity index 94%
rename from Extras/GPUphysics/GPU_physics_demo.cxx
rename to Extras/GPUphysics/GPU_physics_demo.cpp
index debf0d120..fa3f6b945 100644
--- a/Extras/GPUphysics/GPU_physics_demo.cxx
+++ b/Extras/GPUphysics/GPU_physics_demo.cpp
@@ -429,12 +429,13 @@ void initCubeVBO ()
     cubeShader = NULL ;
   else
   {
+	//the filenames have additional path to make it easier for some platforms
     if ( noVertexTextureSupport )
-      cubeShader = new GLSL_ShaderPair ( "CubeShader", "cubeShaderNoTexture.vert",
-                                                       "cubeShader.frag" ) ;
+      cubeShader = new GLSL_ShaderPair ( "CubeShader", "../../Extras/GPUphysics/cubeShaderNoTexture.vert",
+                                                       "../../Extras/GPUphysics/cubeShader.frag" ) ;
     else
-      cubeShader = new GLSL_ShaderPair ( "CubeShader", "cubeShader.vert",
-                                                       "cubeShader.frag" ) ;
+      cubeShader = new GLSL_ShaderPair ( "CubeShader", "../../Extras/GPUphysics/cubeShader.vert",
+                                                       "../../Extras/GPUphysics/cubeShader.frag" ) ;
     assert ( cubeShader -> compiledOK () ) ;
   }
 }
diff --git a/Extras/GPUphysics/Makefile b/Extras/GPUphysics/Makefile
index 0745b2ddd..3de7af193 100644
--- a/Extras/GPUphysics/Makefile
+++ b/Extras/GPUphysics/Makefile
@@ -5,14 +5,14 @@ OBJS  = GPU_physics_demo.o fboSupport.o shaderSupport.o
 all: ${OBJS}
 	g++ -o GPU_physics_demo ${OBJS} -lglut -lGLEW -lGL
 
-shaderSupport.o : shaderSupport.cxx ${HDRS}
-	g++ -c shaderSupport.cxx
+shaderSupport.o : shaderSupport.cpp ${HDRS}
+	g++ -c shaderSupport.cpp
 
-fboSupport.o : fboSupport.cxx ${HDRS}
-	g++ -c fboSupport.cxx
+fboSupport.o : fboSupport.cpp ${HDRS}
+	g++ -c fboSupport.cpp
 
-GPU_physics_demo.o : GPU_physics_demo.cxx ${HDRS}
-	g++ -c GPU_physics_demo.cxx
+GPU_physics_demo.o : GPU_physics_demo.cpp ${HDRS}
+	g++ -c GPU_physics_demo.cpp
 
 clean:
 	-rm -f ${OBJS}
diff --git a/Extras/GPUphysics/Makefile.Mac b/Extras/GPUphysics/Makefile.Mac
index b0ef9ba00..78c3e897c 100644
--- a/Extras/GPUphysics/Makefile.Mac
+++ b/Extras/GPUphysics/Makefile.Mac
@@ -5,14 +5,14 @@ OBJS  = GPU_physics_demo.o fboSupport.o shaderSupport.o
 all: ${OBJS}
 	g++ -framework GLUT -framework OpenGL -L"/System/Library/Frameworks/OpenGL.framework/Libraries" -lGL -lGLU -o GPU_physics_demo ${OBJS} -L"/System/Library/Frameworks/OpenGL.framework/Libraries"  -lGLU -lGLEW -lGL -lGLU -lobjc
 
-shaderSupport.o : shaderSupport.cxx ${HDRS}
-	g++ -c shaderSupport.cxx
+shaderSupport.o : shaderSupport.cpp ${HDRS}
+	g++ -c shaderSupport.cpp
 
-fboSupport.o : fboSupport.cxx ${HDRS}
-	g++ -c fboSupport.cxx
+fboSupport.o : fboSupport.cpp ${HDRS}
+	g++ -c fboSupport.cpp
 
-GPU_physics_demo.o : GPU_physics_demo.cxx ${HDRS}
-	g++ -c GPU_physics_demo.cxx
+GPU_physics_demo.o : GPU_physics_demo.cpp ${HDRS}
+	g++ -c GPU_physics_demo.cpp
 
 clean:
 	-rm -f ${OBJS}
diff --git a/Extras/GPUphysics/fboSupport.cxx b/Extras/GPUphysics/fboSupport.cpp
similarity index 100%
rename from Extras/GPUphysics/fboSupport.cxx
rename to Extras/GPUphysics/fboSupport.cpp
diff --git a/Extras/GPUphysics/shaderSupport.cxx b/Extras/GPUphysics/shaderSupport.cpp
similarity index 100%
rename from Extras/GPUphysics/shaderSupport.cxx
rename to Extras/GPUphysics/shaderSupport.cpp