diff --git a/OpenRA.Game/Traits/TraitsInterfaces.cs b/OpenRA.Game/Traits/TraitsInterfaces.cs
index f065e28d93..84a8bbdf6c 100644
--- a/OpenRA.Game/Traits/TraitsInterfaces.cs
+++ b/OpenRA.Game/Traits/TraitsInterfaces.cs
@@ -324,7 +324,7 @@ namespace OpenRA.Traits
 
 	public interface IPositionableInfo : IOccupySpaceInfo
 	{
-		bool CanEnterCell(World world, Actor self, CPos cell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All);
+		bool CanEnterCell(World world, Actor self, CPos cell, SubCell subCell = SubCell.FullCell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All);
 	}
 
 	public interface IPositionable : IOccupySpace
diff --git a/OpenRA.Mods.Cnc/Traits/TDGunboat.cs b/OpenRA.Mods.Cnc/Traits/TDGunboat.cs
index 73857b9d18..00bacbde33 100644
--- a/OpenRA.Mods.Cnc/Traits/TDGunboat.cs
+++ b/OpenRA.Mods.Cnc/Traits/TDGunboat.cs
@@ -47,12 +47,9 @@ namespace OpenRA.Mods.Cnc.Traits
 		bool IOccupySpaceInfo.SharesCell { get { return false; } }
 
 		// Used to determine if actor can spawn
-		public bool CanEnterCell(World world, Actor self, CPos cell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
+		public bool CanEnterCell(World world, Actor self, CPos cell, SubCell subCell = SubCell.FullCell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
 		{
-			if (!world.Map.Contains(cell))
-				return false;
-
-			return true;
+			return world.Map.Contains(cell);
 		}
 	}
 
diff --git a/OpenRA.Mods.Common/Traits/Air/Aircraft.cs b/OpenRA.Mods.Common/Traits/Air/Aircraft.cs
index c48ef71192..f093e118f0 100644
--- a/OpenRA.Mods.Common/Traits/Air/Aircraft.cs
+++ b/OpenRA.Mods.Common/Traits/Air/Aircraft.cs
@@ -158,7 +158,7 @@ namespace OpenRA.Mods.Common.Traits
 		bool IOccupySpaceInfo.SharesCell { get { return false; } }
 
 		// Used to determine if an aircraft can spawn landed
-		public bool CanEnterCell(World world, Actor self, CPos cell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
+		public bool CanEnterCell(World world, Actor self, CPos cell, SubCell subCell = SubCell.FullCell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
 		{
 			if (!world.Map.Contains(cell))
 				return false;
@@ -173,6 +173,7 @@ namespace OpenRA.Mods.Common.Traits
 			if (check == BlockedByActor.None)
 				return true;
 
+			// Since aircraft don't share cells, we don't pass the subCell parameter
 			return !world.ActorMap.GetActorsAt(cell).Any(x => x != ignoreActor);
 		}
 
diff --git a/OpenRA.Mods.Common/Traits/Crates/Crate.cs b/OpenRA.Mods.Common/Traits/Crates/Crate.cs
index 21e147f083..95f4c2a6cb 100644
--- a/OpenRA.Mods.Common/Traits/Crates/Crate.cs
+++ b/OpenRA.Mods.Common/Traits/Crates/Crate.cs
@@ -40,8 +40,9 @@ namespace OpenRA.Mods.Common.Traits
 
 		bool IOccupySpaceInfo.SharesCell { get { return false; } }
 
-		public bool CanEnterCell(World world, Actor self, CPos cell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
+		public bool CanEnterCell(World world, Actor self, CPos cell, SubCell subCell = SubCell.FullCell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
 		{
+			// Since crates don't share cells and GetAvailableSubCell only returns SubCell.Full or SubCell.Invalid, we ignore the subCell parameter
 			return GetAvailableSubCell(world, cell, ignoreActor, check) != SubCell.Invalid;
 		}
 
diff --git a/OpenRA.Mods.Common/Traits/Husk.cs b/OpenRA.Mods.Common/Traits/Husk.cs
index fb5df595ff..28516ff0b6 100644
--- a/OpenRA.Mods.Common/Traits/Husk.cs
+++ b/OpenRA.Mods.Common/Traits/Husk.cs
@@ -42,7 +42,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		bool IOccupySpaceInfo.SharesCell { get { return false; } }
 
-		public bool CanEnterCell(World world, Actor self, CPos cell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
+		public bool CanEnterCell(World world, Actor self, CPos cell, SubCell subCell = SubCell.FullCell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
 		{
 			// IPositionable*Info*.CanEnterCell is only ever used for things like exiting production facilities,
 			// all places relevant for husks check IPositionable.CanEnterCell instead, so we can safely set this to true.
diff --git a/OpenRA.Mods.Common/Traits/Mobile.cs b/OpenRA.Mods.Common/Traits/Mobile.cs
index 0180f2e82f..8884b47685 100644
--- a/OpenRA.Mods.Common/Traits/Mobile.cs
+++ b/OpenRA.Mods.Common/Traits/Mobile.cs
@@ -86,7 +86,7 @@ namespace OpenRA.Mods.Common.Traits
 		// initialized and used by CanEnterCell
 		Locomotor locomotor;
 
-		public bool CanEnterCell(World world, Actor self, CPos cell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
+		public bool CanEnterCell(World world, Actor self, CPos cell, SubCell subCell = SubCell.FullCell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
 		{
 			// PERF: Avoid repeated trait queries on the hot path
 			if (locomotor == null)
@@ -96,7 +96,7 @@ namespace OpenRA.Mods.Common.Traits
 			if (locomotor.MovementCostForCell(cell) == short.MaxValue)
 				return false;
 
-			return locomotor.CanMoveFreelyInto(self, cell, check, ignoreActor);
+			return locomotor.CanMoveFreelyInto(self, cell, subCell, check, ignoreActor);
 		}
 
 		public IReadOnlyDictionary<CPos, SubCell> OccupiedCells(ActorInfo info, CPos location, SubCell subCell = SubCell.Any)
@@ -501,7 +501,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public bool CanEnterCell(CPos cell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
 		{
-			return Info.CanEnterCell(self.World, self, cell, ignoreActor, check);
+			return Info.CanEnterCell(self.World, self, cell, SubCell.FullCell, ignoreActor, check);
 		}
 
 		#endregion
diff --git a/OpenRA.Mods.Common/Traits/Production.cs b/OpenRA.Mods.Common/Traits/Production.cs
index c8b4f7a295..68149dd18d 100644
--- a/OpenRA.Mods.Common/Traits/Production.cs
+++ b/OpenRA.Mods.Common/Traits/Production.cs
@@ -130,7 +130,7 @@ namespace OpenRA.Mods.Common.Traits
 			self.NotifyBlocker(self.Location + s.ExitCell);
 
 			return mobileInfo == null ||
-				mobileInfo.CanEnterCell(self.World, self, self.Location + s.ExitCell, self);
+				mobileInfo.CanEnterCell(self.World, self, self.Location + s.ExitCell, ignoreActor: self);
 		}
 	}
 }
diff --git a/OpenRA.Mods.Common/Traits/World/Locomotor.cs b/OpenRA.Mods.Common/Traits/World/Locomotor.cs
index 93cd0c0645..cf67bbeb16 100644
--- a/OpenRA.Mods.Common/Traits/World/Locomotor.cs
+++ b/OpenRA.Mods.Common/Traits/World/Locomotor.cs
@@ -246,6 +246,11 @@ namespace OpenRA.Mods.Common.Traits
 
 		// Determines whether the actor is blocked by other Actors
 		public bool CanMoveFreelyInto(Actor actor, CPos cell, BlockedByActor check, Actor ignoreActor)
+		{
+			return CanMoveFreelyInto(actor, cell, SubCell.FullCell, check, ignoreActor);
+		}
+
+		public bool CanMoveFreelyInto(Actor actor, CPos cell, SubCell subCell, BlockedByActor check, Actor ignoreActor)
 		{
 			var cellCache = GetCache(cell);
 			var cellFlag = cellCache.CellFlag;
@@ -296,7 +301,8 @@ namespace OpenRA.Mods.Common.Traits
 					return false;
 			}
 
-			foreach (var otherActor in world.ActorMap.GetActorsAt(cell))
+			var otherActors = subCell == SubCell.FullCell ? world.ActorMap.GetActorsAt(cell) : world.ActorMap.GetActorsAt(cell, subCell);
+			foreach (var otherActor in otherActors)
 				if (IsBlockedBy(actor, otherActor, ignoreActor, check, cellFlag))
 					return false;