diff --git a/src/AcDream.App/Streaming/GpuWorldState.cs b/src/AcDream.App/Streaming/GpuWorldState.cs
index 1e7702b..0d5b647 100644
--- a/src/AcDream.App/Streaming/GpuWorldState.cs
+++ b/src/AcDream.App/Streaming/GpuWorldState.cs
@@ -51,10 +51,21 @@ public sealed class GpuWorldState
     /// Append an entity to a specific landblock's slot. Used by the live
     /// CreateObject path where the server spawns entities into an already-
     /// loaded landblock after the initial hydration pass.
+    ///
+    /// <para>
+    /// The server's <c>landblockId</c> is in cell-resolved form
+    /// (<c>0xAAAA00CC</c>: high byte X, second byte Y, low 16 bits cell
+    /// index within the landblock). The streaming system stores landblocks
+    /// keyed by their canonical <c>0xAAAA0xFFFF</c> form. Canonicalize on
+    /// the way in so callers don't have to think about it — masking with
+    /// <c>0xFFFF0000u | 0xFFFFu</c> drops the cell index and selects the
+    /// LandBlock dat terminator.
+    /// </para>
     /// </summary>
     public void AppendLiveEntity(uint landblockId, WorldEntity entity)
     {
-        if (!_loaded.TryGetValue(landblockId, out var lb))
+        uint canonicalLandblockId = (landblockId & 0xFFFF0000u) | 0xFFFFu;
+        if (!_loaded.TryGetValue(canonicalLandblockId, out var lb))
             return;
 
         // LoadedLandblock.Entities is an IReadOnlyList. Rebuild the
@@ -64,7 +75,7 @@ public sealed class GpuWorldState
         var newEntities = new List<WorldEntity>(lb.Entities.Count + 1);
         newEntities.AddRange(lb.Entities);
         newEntities.Add(entity);
-        _loaded[landblockId] = new LoadedLandblock(lb.LandblockId, lb.Heightmap, newEntities);
+        _loaded[canonicalLandblockId] = new LoadedLandblock(lb.LandblockId, lb.Heightmap, newEntities);
         RebuildFlatView();
     }