diff --git a/atom-publisher-lib/src/main/scala/com/gu/atom/util/JsonSupport.scala b/atom-publisher-lib/src/main/scala/com/gu/atom/util/JsonSupport.scala
index d9132e9..7729c84 100644
--- a/atom-publisher-lib/src/main/scala/com/gu/atom/util/JsonSupport.scala
+++ b/atom-publisher-lib/src/main/scala/com/gu/atom/util/JsonSupport.scala
@@ -66,8 +66,8 @@ object JsonSupport {
         val fixedJson = {
           val nestedDataFieldName = atomType.toLowerCase
 
-          //Special case for commonsDivision because the scrooge enum value loses the casing
-          if (data(nestedDataFieldName).nonEmpty || nestedDataFieldName == "commonsdivision") c.value
+          //Special case for commonsDivision and multimediaSlideshow because the scrooge enum value loses the casing
+          if (data(nestedDataFieldName).nonEmpty || nestedDataFieldName == "commonsdivision" || nestedDataFieldName == "multimediaslideshow") c.value
           else {
             //Add the union type name under `data`
             val newData = JsonObject.fromIterable(Seq(nestedDataFieldName -> dataJson))
diff --git a/build.sbt b/build.sbt
index aa85310..63ab0cc 100644
--- a/build.sbt
+++ b/build.sbt
@@ -6,7 +6,7 @@ name := "atom-maker-lib"
 
 lazy val artifactProductionSettings = Seq(
   organization := "com.gu",
-  scalaVersion := "2.13.13",
+  scalaVersion := "2.13.14",
   licenses := Seq(License.Apache2),
   scalacOptions := Seq("-deprecation", "-feature", "-release:11")
 )
diff --git a/project/BuildVars.scala b/project/BuildVars.scala
index f003701..43d8b91 100644
--- a/project/BuildVars.scala
+++ b/project/BuildVars.scala
@@ -2,7 +2,7 @@ import sbt._
 
 object BuildVars {
   lazy val awsVersion         = "1.12.680"
-  lazy val contentAtomVersion = "12.0.1"
+  lazy val contentAtomVersion = "13.1.0-PREVIEW.glspike-multimedia-atom.2026-08-03T1406.314057f2"
   lazy val scroogeVersion     = "22.1.0"
   lazy val playVersion        = "3.0.10"
   lazy val mockitoVersion     = "4.11.0"