diff --git a/build.sbt b/build.sbt
index 1a972764..d27a8428 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,15 +1,14 @@
 // See LICENSE for license details.
 
 val defaultVersions = Map(
-  "chisel3" -> "3.5.1",
-  "chisel-iotesters" -> "2.5.1"
+  "chisel3" -> "3.5.5",
+  "chisel-iotesters" -> "2.5.5"
 )
 
 organization := "edu.berkeley.cs"
 version := "0.4-SNAPSHOT"
 name := "tapeout"
-scalaVersion := "2.12.13"
-crossScalaVersions := Seq("2.12.13", "2.13.6")
+scalaVersion := "2.13.10"
 scalacOptions := Seq("-deprecation", "-feature", "-language:reflectiveCalls")
 Test / scalacOptions ++= Seq("-language:reflectiveCalls")
 fork := true
diff --git a/project/build.properties b/project/build.properties
index 0837f7a1..46e43a97 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.3.13
+sbt.version=1.8.2