diff --git a/progs/xdemos/pbdemo.c b/progs/xdemos/pbdemo.c
index 2573209336c..277df729246 100644
--- a/progs/xdemos/pbdemo.c
+++ b/progs/xdemos/pbdemo.c
@@ -131,6 +131,7 @@ MakePbuffer( Display *dpy, int screen, int width, int height )
       fbConfigs = ChooseFBConfig(dpy, screen, fbAttribs[attempt], &nConfigs);
       if (nConfigs==0 || !fbConfigs) {
          printf("Note: glXChooseFBConfig(%s) failed\n", fbString[attempt]);
+         XFree(fbConfigs);
          continue;
       }