diff --git a/src/mesa/drivers/x11/fakeglx.c b/src/mesa/drivers/x11/fakeglx.c
index 445d43b6539..916296d1972 100644
--- a/src/mesa/drivers/x11/fakeglx.c
+++ b/src/mesa/drivers/x11/fakeglx.c
@@ -1983,6 +1983,9 @@ Fake_glXChooseFBConfig( Display *dpy, int screen,
 {
    XMesaVisual xmvis;
 
+   /* register ourselves as an extension on this display */
+   register_with_display(dpy);
+
    if (!attribList || !attribList[0]) {
       /* return list of all configs (per GLX_SGIX_fbconfig spec) */
       return Fake_glXGetFBConfigs(dpy, screen, nitems);