diff --git a/runners/spark/3/job-server/build.gradle b/runners/spark/3/job-server/build.gradle
index a3aa69085a8b..d11a1a8edb13 100644
--- a/runners/spark/3/job-server/build.gradle
+++ b/runners/spark/3/job-server/build.gradle
@@ -29,3 +29,12 @@ project.ext {
 
 // Load the main build script which contains all build logic.
 apply from: "$basePath/spark_job_server.gradle"
+
+
+configurations.runtimeClasspath {
+  resolutionStrategy {
+    // Downgrade the Scala version of the job-server to match the Scala version of a Spark 3.1.2 cluster to prevent
+    // a Scala bug (InvalidClassException when deserializing WrappedArray), see https://github.com/apache/beam/issues/21092
+    force "org.scala-lang:scala-library:2.12.10"
+  }
+}
\ No newline at end of file