diff --git a/.haxerc b/.haxerc
index 4d2d91c..ed33e32 100644
--- a/.haxerc
+++ b/.haxerc
@@ -1 +1,4 @@
-{"version":"3.4.7","resolveLibs":"scoped"}
\ No newline at end of file
+{
+  "version": "4.0.0-rc.1",
+  "resolveLibs": "scoped"
+}
\ No newline at end of file
diff --git a/.vscode/settings.json b/.vscode/settings.json
deleted file mode 100644
index f3a8721..0000000
--- a/.vscode/settings.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-    "haxe.displayConfigurations": [
-        ["tests.hxml"]
-    ]
-}
diff --git a/dev.hxml b/dev.hxml
new file mode 100644
index 0000000..6ce49b2
--- /dev/null
+++ b/dev.hxml
@@ -0,0 +1,6 @@
+tests.hxml
+-lib travix
+-lib tink_macro
+-lib hx3compat
+-js whatever.js
+--no-output
\ No newline at end of file
diff --git a/src/tink/macro/Types.hx b/src/tink/macro/Types.hx
index 5270477..9306d7c 100644
--- a/src/tink/macro/Types.hx
+++ b/src/tink/macro/Types.hx
@@ -126,7 +126,8 @@ class Types {
 
   static public function isSubTypeOf(t:Type, of:Type, ?pos)
     return
-      ECheckType(ECheckType(macro null, toComplex(t)).at(pos), toComplex(of)).at(pos).typeof();
+      if (Context.unify(t, of)) ECheckType(ECheckType(macro null, toComplex(t)).at(pos), toComplex(of)).at(pos).typeof();
+      else Failure(new Error(t.toString() + ' should be ' + of.toString(), pos.sanitize()));
 
   static public function isDynamic(t:Type)
     return switch reduce(t) {
diff --git a/tests/Types.hx b/tests/Types.hx
index f373f6c..a0fb67a 100644
--- a/tests/Types.hx
+++ b/tests/Types.hx
@@ -1,5 +1,6 @@
 package ;
 
+#if macro
 import haxe.macro.Expr;
 import haxe.macro.Context;
 
@@ -20,6 +21,7 @@ class Types extends Base {
     assertFalse(o.isSuccess());
     
   function testIs() {
+    
     assertSuccess(resolve('Int').isSubTypeOf(resolve('Float')));
     assertFailure(resolve('Float').isSubTypeOf(resolve('Int')));
   }  
@@ -41,10 +43,20 @@ class Types extends Base {
     var bool = type(macro : Bool);
     assertTrue(blank().isSubTypeOf(bool).isSuccess());
     assertTrue(bool.isSubTypeOf(blank()).isSuccess());
-    
-    MacroApi.pos().makeBlankType().toString();
   }
 
+  #if haxe4
+  function testFinal() {
+    var t = macro : {
+      final foo:Int;
+    };
+    switch t.toType().sure() {
+      case TAnonymous(_.get().fields => [f]): assertTrue(f.isFinal);
+      default:
+    }
+  }
+  #end
+
   function testExpr() {
     assertEquals('VarChar<255>', (macro : VarChar<255>).toType().sure().toComplex().toString());
   }
@@ -53,4 +65,5 @@ class Types extends Base {
     assertEquals('String', Context.getType('String').toComplex().toString());
     assertEquals('tink.CoreApi.Noise', Context.getType('tink.CoreApi.Noise').toComplex().toString());
   }
-}
\ No newline at end of file
+}
+#end
\ No newline at end of file