diff --git a/OpenRA.Mods.Common/Traits/Sound/AnnounceOnKill.cs b/OpenRA.Mods.Common/Traits/Sound/AnnounceOnKill.cs
index f7f38b014f..9d73077b6d 100644
--- a/OpenRA.Mods.Common/Traits/Sound/AnnounceOnKill.cs
+++ b/OpenRA.Mods.Common/Traits/Sound/AnnounceOnKill.cs
@@ -37,7 +37,7 @@ namespace OpenRA.Mods.Common.Traits.Sound
 			lastAnnounce = -info.Interval * 25;
 		}
 
-		public void AppliedDamage(Actor self, Actor damaged, AttackInfo e)
+		void INotifyAppliedDamage.AppliedDamage(Actor self, Actor damaged, AttackInfo e)
 		{
 			// Don't notify suicides
 			if (e.DamageState == DamageState.Dead && damaged != e.Attacker)
diff --git a/OpenRA.Mods.Common/TraitsInterfaces.cs b/OpenRA.Mods.Common/TraitsInterfaces.cs
index 91c2376df5..309db1a746 100644
--- a/OpenRA.Mods.Common/TraitsInterfaces.cs
+++ b/OpenRA.Mods.Common/TraitsInterfaces.cs
@@ -87,6 +87,7 @@ namespace OpenRA.Mods.Common.Traits
 	public interface INotifyDamage { void Damaged(Actor self, AttackInfo e); }
 	[RequireExplicitImplementation]
 	public interface INotifyKilled { void Killed(Actor self, AttackInfo e); }
+	[RequireExplicitImplementation]
 	public interface INotifyAppliedDamage { void AppliedDamage(Actor self, Actor damaged, AttackInfo e); }
 
 	[RequireExplicitImplementation]