diff --git a/src/Builtin/IsMissingRelationNode.cs b/src/Builtin/IsMissingRelationNode.cs
deleted file mode 100644
index 88664b4..0000000
--- a/src/Builtin/IsMissingRelationNode.cs
+++ /dev/null
@@ -1,9 +0,0 @@
-namespace DCFApixels.DragonECS
-{
-    [System.Serializable]
-    [MetaColor(MetaColor.DragonRose)]
-    [MetaGroup(EcsGraphConsts.PACK_GROUP)]
-    [MetaDescription(EcsConsts.AUTHOR, "...")]
-    [MetaID("1C53321A9301DB70DB84A88611F6C36C")]
-    public struct IsMissingRelationNode : IEcsTagComponent { }
-}
diff --git a/src/Utils/Rels.cs b/src/Utils/Rels.cs
index 8d9c4ff..b2727cc 100644
--- a/src/Utils/Rels.cs
+++ b/src/Utils/Rels.cs
@@ -64,6 +64,8 @@ namespace DCFApixels.DragonECS
         public override string ToString() { return $"arc({start} -> {end})"; }
         #endregion
     }
+    [StructLayout(LayoutKind.Sequential, Pack = 4, Size = 12)]
+    [Serializable]
     public readonly ref struct StartRelEnd
     {
         /// <summary>Start vertex entity ID.</summary>
@@ -118,6 +120,8 @@ namespace DCFApixels.DragonECS
         public override string ToString() { return $"arc({start} --({rel})-> {end})"; }
         #endregion
     }
+    [StructLayout(LayoutKind.Sequential, Pack = 4, Size = 8)]
+    [Serializable]
     public readonly ref struct RelEnd
     {
         /// <summary>Relation entity ID.</summary>