diff --git a/src/intermission/intermission.cpp b/src/intermission/intermission.cpp
index 892ac30dd..eebd247e0 100644
--- a/src/intermission/intermission.cpp
+++ b/src/intermission/intermission.cpp
@@ -816,6 +816,7 @@ bool DIntermissionController::NextPage ()
 		// last page
 		return false;
 	}
+	bg.SetInvalid();
 
 	if (mScreen != NULL)
 	{