diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/weapon/melee/Dagger.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/weapon/melee/Dagger.java
index bec236048..322faf51b 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/weapon/melee/Dagger.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/weapon/melee/Dagger.java
@@ -125,7 +125,7 @@ public class Dagger extends MeleeWeapon {
 		}
 
 		wep.beforeAbilityUsed(hero, null);
-		Buff.affect(hero, Invisibility.class, invisTurns-1); //1 fewer turns as ability is instant
+		Buff.prolong(hero, Invisibility.class, invisTurns-1); //1 fewer turns as ability is instant
 
 		Dungeon.hero.sprite.turnTo( Dungeon.hero.pos, target);
 		Dungeon.hero.pos = target;