diff --git a/src/p_enemy.cpp b/src/p_enemy.cpp
index 01e8aafac..3494792e6 100644
--- a/src/p_enemy.cpp
+++ b/src/p_enemy.cpp
@@ -1670,7 +1670,7 @@ bool P_LookForPlayers (AActor *actor, INTBOOL allaround, FLookExParams *params)
 
 		// [RC] Well, let's let special monsters with this flag active be able to see
 		// the player then, eh?
-		if(!(actor->flags & MF6_SEEINVISIBLE)) 
+		if(!(actor->flags6 & MF6_SEEINVISIBLE)) 
 		{
 			if ((player->mo->flags & MF_SHADOW && !(i_compatflags & COMPATF_INVISIBILITY)) ||
 				player->mo->flags3 & MF3_GHOST)