diff --git a/build.sbt b/build.sbt
index b361d1c6f..b0f4b16d2 100644
--- a/build.sbt
+++ b/build.sbt
@@ -896,7 +896,7 @@ lazy val upickle = (projectMatrix in file("json/upickle"))
   .settings(
     name := "upickle",
     libraryDependencies ++= Seq(
-      "com.lihaoyi" %%% "upickle" % "3.3.1"
+      "com.lihaoyi" %%% "upickle" % "4.0.0"
     ),
     scalaTest,
     // using macroRW causes a "match may not be exhaustive" error