diff --git a/src/core/execution/CityExecution.ts b/src/core/execution/CityExecution.ts
index 863ba716e..69d39977d 100644
--- a/src/core/execution/CityExecution.ts
+++ b/src/core/execution/CityExecution.ts
@@ -52,7 +52,6 @@ export class CityExecution implements Execution {
         this.city.tile(),
         this.mg.config().trainStationMaxRange(),
         UnitType.Factory,
-        this.player.id(),
       );
       if (nearbyFactory) {
         this.mg.addExecution(new TrainStationExecution(this.city));
diff --git a/src/core/execution/PortExecution.ts b/src/core/execution/PortExecution.ts
index fc8971b2d..5c7dfc566 100644
--- a/src/core/execution/PortExecution.ts
+++ b/src/core/execution/PortExecution.ts
@@ -97,7 +97,6 @@ export class PortExecution implements Execution {
         this.port.tile(),
         this.mg.config().trainStationMaxRange(),
         UnitType.Factory,
-        this.player.id(),
       );
       if (nearbyFactory) {
         this.mg.addExecution(new TrainStationExecution(this.port));
diff --git a/src/core/game/Game.ts b/src/core/game/Game.ts
index 2486e57ac..2416371da 100644
--- a/src/core/game/Game.ts
+++ b/src/core/game/Game.ts
@@ -673,7 +673,7 @@ export type Game = {
     tile: TileRef,
     searchRange: number,
     type: UnitType,
-    playerId: PlayerID,
+    playerId?: PlayerID,
   ): boolean;
   nearbyUnits(
     tile: TileRef,
diff --git a/src/core/game/GameImpl.ts b/src/core/game/GameImpl.ts
index 91e6ff98d..9d1898910 100644
--- a/src/core/game/GameImpl.ts
+++ b/src/core/game/GameImpl.ts
@@ -752,7 +752,7 @@ export class GameImpl implements Game {
     tile: TileRef,
     searchRange: number,
     type: UnitType,
-    playerId: PlayerID,
+    playerId?: PlayerID,
   ) {
     return this.unitGrid.hasUnitNearby(tile, searchRange, type, playerId);
   }
diff --git a/src/core/game/UnitGrid.ts b/src/core/game/UnitGrid.ts
index 2f17d9ee9..bb8b52d0d 100644
--- a/src/core/game/UnitGrid.ts
+++ b/src/core/game/UnitGrid.ts
@@ -170,12 +170,28 @@ export class UnitGrid {
     return nearby;
   }
 
+  private unitIsInRange(
+    unit: Unit | UnitView,
+    tile: TileRef,
+    rangeSquared: number,
+    playerId?: PlayerID,
+  ): boolean {
+    if (!unit.isActive()) {
+      return false;
+    }
+    if (playerId !== undefined && unit.owner().id() !== playerId) {
+      return false;
+    }
+    const distSquared = this.squaredDistanceFromTile(unit, tile);
+    return distSquared <= rangeSquared;
+  }
+
   // Return true if it finds an owned specific unit in range
   hasUnitNearby(
     tile: TileRef,
     searchRange: number,
     type: UnitType,
-    playerId: PlayerID,
+    playerId?: PlayerID,
   ): boolean {
     const { startGridX, endGridX, startGridY, endGridY } = this.getCellsInRange(
       tile,
@@ -187,11 +203,8 @@ export class UnitGrid {
         const unitSet = this.grid[cy][cx].get(type);
         if (unitSet === undefined) continue;
         for (const unit of unitSet) {
-          if (unit.owner().id() === playerId && unit.isActive()) {
-            const distSquared = this.squaredDistanceFromTile(unit, tile);
-            if (distSquared <= rangeSquared) {
-              return true;
-            }
+          if (this.unitIsInRange(unit, tile, rangeSquared, playerId)) {
+            return true;
           }
         }
       }