diff --git a/OpenRA.Game/OpenRA.Game.csproj b/OpenRA.Game/OpenRA.Game.csproj
index 035ddf3832..e2fad0b42f 100644
--- a/OpenRA.Game/OpenRA.Game.csproj
+++ b/OpenRA.Game/OpenRA.Game.csproj
@@ -168,7 +168,6 @@
     <Compile Include="Support\Program.cs" />
     <Compile Include="Sync.cs" />
     <Compile Include="TraitDictionary.cs" />
-    <Compile Include="Traits\Armor.cs" />
     <Compile Include="Traits\DrawLineToTarget.cs" />
     <Compile Include="Traits\EditorTilesetFilter.cs" />
     <Compile Include="Traits\Health.cs" />
diff --git a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
index a95faa52bd..687d3c95b4 100644
--- a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
+++ b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
@@ -260,6 +260,7 @@
     <Compile Include="Traits\Air\TargetableAircraft.cs" />
     <Compile Include="Traits\AppearsOnRadar.cs" />
     <Compile Include="Traits\Armament.cs" />
+    <Compile Include="Traits\Armor.cs" />
     <Compile Include="Traits\AttackMove.cs" />
     <Compile Include="Traits\Attack\AttackBase.cs" />
     <Compile Include="Traits\Attack\AttackCharge.cs" />
diff --git a/OpenRA.Game/Traits/Armor.cs b/OpenRA.Mods.Common/Traits/Armor.cs
similarity index 90%
rename from OpenRA.Game/Traits/Armor.cs
rename to OpenRA.Mods.Common/Traits/Armor.cs
index 0eed1db5de..04064cd913 100644
--- a/OpenRA.Game/Traits/Armor.cs
+++ b/OpenRA.Mods.Common/Traits/Armor.cs
@@ -8,7 +8,9 @@
  */
 #endregion
 
-namespace OpenRA.Traits
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits
 {
 	[Desc("Used to define weapon efficiency modifiers with different percentages per Type.")]
 	public class ArmorInfo : TraitInfo<Armor>
diff --git a/OpenRA.Mods.Common/Warheads/DamageWarhead.cs b/OpenRA.Mods.Common/Warheads/DamageWarhead.cs
index 8abeec4f1f..b9d6f3e169 100644
--- a/OpenRA.Mods.Common/Warheads/DamageWarhead.cs
+++ b/OpenRA.Mods.Common/Warheads/DamageWarhead.cs
@@ -9,6 +9,7 @@
 #endregion
 
 using System.Collections.Generic;
+using OpenRA.Mods.Common.Traits;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Warheads