diff --git a/src/karaxdsl.nim b/src/karaxdsl.nim
index 5ba525a..5553d8f 100644
--- a/src/karaxdsl.nim
+++ b/src/karaxdsl.nim
@@ -4,7 +4,7 @@ from strutils import startsWith, toLowerAscii
 
 const
   StmtContext = ["kout", "inc", "echo", "dec", "!"]
-  SpecialAttrs = ["id", "class", "value", "key"]
+  SpecialAttrs = ["id", "class", "value", "key", "track"]
 
 proc getName(n: NimNode): string =
   case n.kind
diff --git a/src/vdom.nim b/src/vdom.nim
index 48574de..a80fc10 100644
--- a/src/vdom.nim
+++ b/src/vdom.nim
@@ -102,6 +102,7 @@ type
     kind*: VNodeKind
     key*: VKey
     id*, class*, text*: cstring
+    track*: int
     kids: seq[VNode]
     # even index: key, odd index: value; done this way for memory efficiency:
     attrs: seq[cstring]
@@ -166,7 +167,7 @@ proc getAttr*(n: VNode; key: cstring): cstring =
 
 proc len*(x: VNode): int = x.kids.len
 proc `[]`*(x: VNode; idx: int): VNode = x.kids[idx]
-proc `[]=`*(x: VNode; idx: int, y: VNode) = x.kids[idx] = y
+proc `[]=`*(x: VNode; idx: int; y: VNode) = x.kids[idx] = y
 proc add*(parent, kid: VNode) = parent.kids.add kid
 proc newVNode*(kind: VNodeKind): VNode = VNode(kind: kind, key: -1)