diff --git a/OpenRA.Mods.Common/Traits/Buildings/FootprintPlaceBuildingPreview.cs b/OpenRA.Mods.Common/Traits/Buildings/FootprintPlaceBuildingPreview.cs
index 742516efd8..b5b17f1d59 100644
--- a/OpenRA.Mods.Common/Traits/Buildings/FootprintPlaceBuildingPreview.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/FootprintPlaceBuildingPreview.cs
@@ -52,6 +52,12 @@ namespace OpenRA.Mods.Common.Traits
 		readonly Sprite buildOk;
 		readonly Sprite buildBlocked;
 
+		protected static bool HasFlag(PlaceBuildingCellType value, PlaceBuildingCellType flag)
+		{
+			// PERF: Enum.HasFlag is slower and requires allocations.
+			return (value & flag) == value;
+		}
+
 		public FootprintPlaceBuildingPreviewPreview(WorldRenderer wr, ActorInfo ai, FootprintPlaceBuildingPreviewInfo info, TypeDictionary init)
 		{
 			actorInfo = ai;
@@ -83,8 +89,8 @@ namespace OpenRA.Mods.Common.Traits
 				if ((c.Value & filter) == 0)
 					continue;
 
-				var tile = !c.Value.HasFlag(PlaceBuildingCellType.Invalid) ? buildOk : buildBlocked;
-				var pal = c.Value.HasFlag(PlaceBuildingCellType.LineBuild) ? linePalette : cellPalette;
+				var tile = HasFlag(c.Value, PlaceBuildingCellType.Invalid) ? buildBlocked : buildOk;
+				var pal = HasFlag(c.Value, PlaceBuildingCellType.LineBuild) ? linePalette : cellPalette;
 				var pos = wr.World.Map.CenterOfCell(c.Key);
 				var offset = new WVec(0, 0, topLeftPos.Z - pos.Z);
 				yield return new SpriteRenderable(tile, pos, offset, -511, pal, 1f, true);
diff --git a/OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs b/OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs
index 3dd6c3eae5..7b68f8aa91 100644
--- a/OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs
+++ b/OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs
@@ -74,11 +74,11 @@ namespace OpenRA.Mods.Common.Traits
 				if ((c.Value & filter) == 0)
 					continue;
 
-				var tile = c.Value.HasFlag(PlaceBuildingCellType.Invalid) ? buildBlocked :
+				var tile = HasFlag(c.Value, PlaceBuildingCellType.Invalid) ? buildBlocked :
 					candidateSafeTiles.Contains(c.Key) && info.UnsafeTerrainTypes.Contains(wr.World.Map.GetTerrainInfo(c.Key).Type)
 					? buildUnsafe : buildOk;
 
-				var pal = c.Value.HasFlag(PlaceBuildingCellType.LineBuild) ? linePalette : cellPalette;
+				var pal = HasFlag(c.Value, PlaceBuildingCellType.LineBuild) ? linePalette : cellPalette;
 				var pos = wr.World.Map.CenterOfCell(c.Key);
 				var offset = new WVec(0, 0, topLeftPos.Z - pos.Z);
 				yield return new SpriteRenderable(tile, pos, offset, -511, pal, 1f, true);