diff --git a/code/datums/spells/horsemask.dm b/code/datums/spells/horsemask.dm
index d39ff42ea51..787e58ec9f7 100644
--- a/code/datums/spells/horsemask.dm
+++ b/code/datums/spells/horsemask.dm
@@ -26,7 +26,7 @@
 	if(!target)
 		return
 
-	if((target.type in compatible_mobs) || ishuman(target))
+	if((!target.type in compatible_mobs) || ishuman(target))
 		to_chat(user, "<span class='notice'>It'd be stupid to curse [target] with a horse's head!</span>")
 		return