diff --git a/stepmania/src/RageDisplay_OGL_Helpers.cpp b/stepmania/src/RageDisplay_OGL_Helpers.cpp
index 9757f18f59..7c84cc7a0f 100644
--- a/stepmania/src/RageDisplay_OGL_Helpers.cpp
+++ b/stepmania/src/RageDisplay_OGL_Helpers.cpp
@@ -153,6 +153,8 @@ void GLExt_t::Load( LowLevelWindow *pWind )
 			F( glBufferDataARB ),
 			F( glBufferSubDataARB ),
 			F( glDeleteBuffersARB ),
+			F( glMapBufferARB ),
+			F( glUnmapBufferARB ),
 			{ NULL, NULL },
 		};
 
diff --git a/stepmania/src/RageDisplay_OGL_Helpers.h b/stepmania/src/RageDisplay_OGL_Helpers.h
index 803d91b5db..add4d92f37 100644
--- a/stepmania/src/RageDisplay_OGL_Helpers.h
+++ b/stepmania/src/RageDisplay_OGL_Helpers.h
@@ -74,12 +74,16 @@ struct GLExt_t
 	PFNGLCOLORTABLEPARAMETERIVPROC glGetColorTableParameterivEXT;
 	PFNGLACTIVETEXTUREARBPROC glActiveTextureARB;
 	PFNGLCLIENTACTIVETEXTUREARBPROC glClientActiveTextureARB;
+	PFNGLDRAWRANGEELEMENTSPROC glDrawRangeElements;
+
+	// ARB_vertex_buffer_object:
 	PFNGLGENBUFFERSARBPROC glGenBuffersARB;
 	PFNGLBINDBUFFERARBPROC glBindBufferARB;
 	PFNGLBUFFERDATAARBPROC glBufferDataARB;
 	PFNGLBUFFERSUBDATAARBPROC glBufferSubDataARB;
 	PFNGLDELETEBUFFERSARBPROC glDeleteBuffersARB;
-	PFNGLDRAWRANGEELEMENTSPROC glDrawRangeElements;
+	PFNGLMAPBUFFERARBPROC glMapBufferARB;
+	PFNGLUNMAPBUFFERARBPROC glUnmapBufferARB;
 
 	// GL_ARB_shader_objects:
 	bool m_bGL_ARB_shader_objects;