2 files changed, 8 insertions, 10 deletions
diff --git a/main/core/src/mill/eval/Evaluator.scala b/main/core/src/mill/eval/Evaluator.scala
index 563d7b63..2aafdb7a 100644
--- a/main/core/src/mill/eval/Evaluator.scala
+++ b/main/core/src/mill/eval/Evaluator.scala
@@ -11,7 +11,6 @@ import mill.eval.Result.OuterStack
 import mill.util
 import mill.util._
 import mill.util.Strict.Agg
-import upickle.Js
 
 import scala.collection.mutable
 import scala.util.control.NonFatal
@@ -346,7 +345,7 @@ case class Evaluator(home: os.Path,
 
 
 object Evaluator{
-  case class Cached(value: Js.Value,
+  case class Cached(value: ujson.Value,
                     valueHash: Int,
                     inputsHash: Int)
   object Cached{
diff --git a/main/core/src/mill/util/JsonFormatters.scala b/main/core/src/mill/util/JsonFormatters.scala
index e2c3073f..dba599f7 100644
--- a/main/core/src/mill/util/JsonFormatters.scala
+++ b/main/core/src/mill/util/JsonFormatters.scala
@@ -1,6 +1,5 @@
 package mill.util
 
-import upickle.Js
 import upickle.default.{ReadWriter => RW}
 import scala.util.matching.Regex
 object JsonFormatters extends JsonFormatters
@@ -29,14 +28,14 @@ trait JsonFormatters {
   implicit lazy val modFormat: RW[coursier.Module] = upickle.default.macroRW
   implicit lazy val depFormat: RW[coursier.Dependency]= upickle.default.macroRW
   implicit lazy val attrFormat: RW[coursier.Attributes] = upickle.default.macroRW
-  implicit val stackTraceRW = upickle.default.readwriter[Js.Obj].bimap[StackTraceElement](
-    ste => Js.Obj(
-      "declaringClass" -> Js.Str(ste.getClassName),
-      "methodName" -> Js.Str(ste.getMethodName),
-      "fileName" -> Js.Str(ste.getFileName),
-      "lineNumber" -> Js.Num(ste.getLineNumber)
+  implicit val stackTraceRW = upickle.default.readwriter[ujson.Obj].bimap[StackTraceElement](
+    ste => ujson.Obj(
+      "declaringClass" -> ujson.Str(ste.getClassName),
+      "methodName" -> ujson.Str(ste.getMethodName),
+      "fileName" -> ujson.Str(ste.getFileName),
+      "lineNumber" -> ujson.Num(ste.getLineNumber)
     ),
-    {case json: Js.Obj =>
+    {case json: ujson.Obj =>
       new StackTraceElement(
         json("declaringClass").str.toString,
         json("methodName").str.toString,