diff --git a/12to11.conf b/12to11.conf
index 588ead1..30cda9d 100644
--- a/12to11.conf
+++ b/12to11.conf
@@ -21,6 +21,7 @@ WAYLAND_SCANNER	= wayland-scanner
 
  WAYLAND_CLIENT = -lwayland-client
             PNG = -lpng
+            GBM = -lgbm
 
 XCOMM #define BuildTests