diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/GnollGeomancer.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/GnollGeomancer.java
index 42cc06a97..da918dfda 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/GnollGeomancer.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/GnollGeomancer.java
@@ -135,6 +135,13 @@ public class GnollGeomancer extends Mob {
 				|| hasSapper();
 	}
 
+	@Override
+	public boolean add(Buff buff) {
+		//immune to buffs and debuff (except its own rock armor) while sleeping
+		if (state == SLEEPING && !(buff instanceof RockArmor))  return false;
+		else                                                    return super.add(buff);
+	}
+
 	@Override
 	public int damageRoll() {
 		return Random.NormalIntRange( 3, 6 );