diff --git a/OpenRA.Mods.Common/AI/AttackOrFleeFuzzy.cs b/OpenRA.Mods.Common/AI/AttackOrFleeFuzzy.cs
index fc229fe4d5..8ba55a2971 100644
--- a/OpenRA.Mods.Common/AI/AttackOrFleeFuzzy.cs
+++ b/OpenRA.Mods.Common/AI/AttackOrFleeFuzzy.cs
@@ -12,8 +12,8 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using AI.Fuzzy.Library;
-using OpenRA.GameRules;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Mods.Common.Warheads;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.AI
@@ -191,13 +191,13 @@ namespace OpenRA.Mods.Common.AI
 
 		protected float RelativePower(IEnumerable<Actor> own, IEnumerable<Actor> enemy)
 		{
-			return RelativeValue(own, enemy, 100, SumOfValues<AttackBase>, (Actor a) =>
+			return RelativeValue(own, enemy, 100, SumOfValues<AttackBase>, a =>
 			{
 				var sumOfDamage = 0;
 				var arms = a.TraitsImplementing<Armament>();
 				foreach (var arm in arms)
 				{
-					var warhead = arm.Weapon.Warheads.Select(w => w as DamageWarhead).FirstOrDefault(w => w != null);
+					var warhead = arm.Weapon.Warheads.OfType<DamageWarhead>().FirstOrDefault();
 					if (warhead != null)
 						sumOfDamage += warhead.Damage;
 				}
diff --git a/OpenRA.Mods.Common/Lint/CheckDeathTypes.cs b/OpenRA.Mods.Common/Lint/CheckDeathTypes.cs
index b3c6b427e9..d4f4276563 100644
--- a/OpenRA.Mods.Common/Lint/CheckDeathTypes.cs
+++ b/OpenRA.Mods.Common/Lint/CheckDeathTypes.cs
@@ -10,8 +10,8 @@
 
 using System;
 using System.Linq;
-using OpenRA.GameRules;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Mods.Common.Warheads;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Lint
diff --git a/OpenRA.Mods.Common/Traits/Attack/AttackBase.cs b/OpenRA.Mods.Common/Traits/Attack/AttackBase.cs
index 0cca327725..7f60c9e0bd 100644
--- a/OpenRA.Mods.Common/Traits/Attack/AttackBase.cs
+++ b/OpenRA.Mods.Common/Traits/Attack/AttackBase.cs
@@ -13,7 +13,7 @@ using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
 using OpenRA.Activities;
-using OpenRA.GameRules;
+using OpenRA.Mods.Common.Warheads;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Traits
@@ -101,8 +101,11 @@ namespace OpenRA.Mods.Common.Traits
 		{
 			get
 			{
+				if (IsTraitDisabled)
+					yield break;
+
 				var armament = Armaments.FirstOrDefault(a => a.Weapon.Warheads.Any(w => (w is DamageWarhead)));
-				if (armament == null || IsTraitDisabled)
+				if (armament == null)
 					yield break;
 
 				var negativeDamage = (armament.Weapon.Warheads.FirstOrDefault(w => (w is DamageWarhead)) as DamageWarhead).Damage < 0;
diff --git a/OpenRA.Mods.Common/UtilityCommands/ActorStatsExport.cs b/OpenRA.Mods.Common/UtilityCommands/ActorStatsExport.cs
index 9ae4a9510d..ab7368b82c 100644
--- a/OpenRA.Mods.Common/UtilityCommands/ActorStatsExport.cs
+++ b/OpenRA.Mods.Common/UtilityCommands/ActorStatsExport.cs
@@ -12,8 +12,8 @@ using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Linq;
-using OpenRA.GameRules;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Mods.Common.Warheads;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.UtilityCommands
diff --git a/OpenRA.Mods.Common/Warheads/HealthPercentageDamageWarhead.cs b/OpenRA.Mods.Common/Warheads/HealthPercentageDamageWarhead.cs
index a2232f7c3e..bdc7b03fbd 100644
--- a/OpenRA.Mods.Common/Warheads/HealthPercentageDamageWarhead.cs
+++ b/OpenRA.Mods.Common/Warheads/HealthPercentageDamageWarhead.cs
@@ -8,11 +8,8 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
-using OpenRA.Effects;
-using OpenRA.GameRules;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Warheads
diff --git a/OpenRA.Mods.Common/Warheads/SpreadDamageWarhead.cs b/OpenRA.Mods.Common/Warheads/SpreadDamageWarhead.cs
index 5a1c1fa8fb..18723907f3 100644
--- a/OpenRA.Mods.Common/Warheads/SpreadDamageWarhead.cs
+++ b/OpenRA.Mods.Common/Warheads/SpreadDamageWarhead.cs
@@ -10,9 +10,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using OpenRA.Effects;
-using OpenRA.GameRules;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Warheads
diff --git a/OpenRA.Mods.D2k/Warheads/ChangeOwnerWarhead.cs b/OpenRA.Mods.D2k/Warheads/ChangeOwnerWarhead.cs
index ee7fbdd758..4c253f9e39 100644
--- a/OpenRA.Mods.D2k/Warheads/ChangeOwnerWarhead.cs
+++ b/OpenRA.Mods.D2k/Warheads/ChangeOwnerWarhead.cs
@@ -9,7 +9,7 @@
 #endregion
 
 using System.Collections.Generic;
-using OpenRA.GameRules;
+using OpenRA.Mods.Common.Warheads;
 using OpenRA.Mods.D2k.Traits;
 using OpenRA.Traits;
 
@@ -30,11 +30,12 @@ namespace OpenRA.Mods.D2k.Warheads
 
 			foreach (var a in actors)
 			{
-				if (a.Owner == firedBy.Owner) // don't do anything on friendly fire
+				// Don't do anything on friendly fire
+				if (a.Owner == firedBy.Owner)
 					continue;
 
 				if (Duration == 0)
-					a.ChangeOwner(firedBy.Owner); // permanent
+					a.ChangeOwner(firedBy.Owner); // Permanent
 				else
 				{
 					var tempOwnerManager = a.TraitOrDefault<TemporaryOwnerManager>();
@@ -44,7 +45,8 @@ namespace OpenRA.Mods.D2k.Warheads
 					tempOwnerManager.ChangeOwner(a, firedBy.Owner, Duration);
 				}
 
-				a.CancelActivity(); // stop shooting, you have got new enemies
+				// Stop shooting, you have new enemies
+				a.CancelActivity();
 			}
 		}
 	}