diff --git a/src/concurrent/fan/ActorMsg.fan b/src/concurrent/fan/ActorMsg.fan
index 64802f958..0f20cd266 100644
--- a/src/concurrent/fan/ActorMsg.fan
+++ b/src/concurrent/fan/ActorMsg.fan
@@ -13,20 +13,20 @@
 const class ActorMsg
 {
   ** Constructor with zero arguments
-  new make0(Str id)
+  new make0(Obj id)
   {
     this.id = id
   }
 
   ** Constructor with one argument
-  new make1(Str id, Obj? a)
+  new make1(Obj id, Obj? a)
   {
     this.id = id
     this.a  = a
   }
 
   ** Constructor with two arguments
-  new make2(Str id, Obj? a, Obj? b)
+  new make2(Obj id, Obj? a, Obj? b)
   {
     this.id = id
     this.a  = a
@@ -34,7 +34,7 @@ const class ActorMsg
   }
 
   ** Constructor with three arguments
-  new make3(Str id, Obj? a, Obj? b, Obj? c)
+  new make3(Obj id, Obj? a, Obj? b, Obj? c)
   {
     this.id = id
     this.a  = a
@@ -43,7 +43,7 @@ const class ActorMsg
   }
 
   ** Constructor with four arguments
-  new make4(Str id, Obj? a, Obj? b, Obj? c, Obj? d)
+  new make4(Obj id, Obj? a, Obj? b, Obj? c, Obj? d)
   {
     this.id = id
     this.a  = a
@@ -53,7 +53,7 @@ const class ActorMsg
   }
 
   ** Constructor with five arguments
-  new make5(Str id, Obj? a, Obj? b, Obj? c, Obj? d, Obj? e)
+  new make5(Obj id, Obj? a, Obj? b, Obj? c, Obj? d, Obj? e)
   {
     this.id = id
     this.a  = a
@@ -63,8 +63,8 @@ const class ActorMsg
     this.e  = e
   }
 
-  ** Message identifier key
-  const Str id
+  ** Message identifier key, typically string or enum
+  const Obj id
 
   ** Argument a
   const Obj? a
diff --git a/src/concurrent/test/ActorTest.fan b/src/concurrent/test/ActorTest.fan
index db46c38de..303327cbe 100644
--- a/src/concurrent/test/ActorTest.fan
+++ b/src/concurrent/test/ActorTest.fan
@@ -938,6 +938,10 @@ class ActorTest : Test
     verifyMsg(ActorMsg("foo", "a", "b", "c", "d"), 4, "a", "b", "c", "d", null)
     verifyMsg(ActorMsg("foo", "a", "b", "c", "d", "e"), 5, "a", "b", "c", "d", "e")
     verifyMsg(ActorMsg("foo", "a", "b", null, "d", "e"), 5, "a", "b", null, "d", "e")
+
+    m := ActorMsg(123, "alpha")
+    verifyEq(m.id, 123)
+    verifyEq(m.a, "alpha")
   }
 
   Void verifyMsg(ActorMsg m, Int count, Obj? a, Obj? b, Obj? c, Obj? d, Obj? e)