diff --git a/src/core/GameRunner.ts b/src/core/GameRunner.ts
index eddb1223d..af063633f 100644
--- a/src/core/GameRunner.ts
+++ b/src/core/GameRunner.ts
@@ -181,9 +181,13 @@ export class GameRunner {
     let packedTileUpdates: BigUint64Array;
     const tileUpdates = updates[GameUpdateType.Tile];
     if (this.tileUpdateSink !== undefined) {
+      const seenTiles = new Set<TileRef>();
       for (const u of tileUpdates) {
         const tileRef = Number(u.update >> 16n) as TileRef;
-        this.tileUpdateSink(tileRef);
+        if (!seenTiles.has(tileRef)) {
+          seenTiles.add(tileRef);
+          this.tileUpdateSink(tileRef);
+        }
       }
       packedTileUpdates = new BigUint64Array();
     } else {