diff --git a/build.sbt b/build.sbt
index 560eadbd..4168d985 100644
--- a/build.sbt
+++ b/build.sbt
@@ -11,7 +11,7 @@ ThisBuild / developers := List(
 ThisBuild / tlSitePublishBranch := Some("main")
 
 val Scala213 = "2.13.14"
-ThisBuild / crossScalaVersions := Seq("2.12.19", Scala213, "3.3.4")
+ThisBuild / crossScalaVersions := Seq("2.12.20", Scala213, "3.3.4")
 ThisBuild / scalaVersion := Scala213 // the default Scala
 
 // Jetty 10+, for testing, requires Java 11.