diff --git a/spark/src/test/scala/ai/chronon/spark/test/FetcherTest.scala b/spark/src/test/scala/ai/chronon/spark/test/FetcherTest.scala
index 555ccbae9..3fda7ed12 100644
--- a/spark/src/test/scala/ai/chronon/spark/test/FetcherTest.scala
+++ b/spark/src/test/scala/ai/chronon/spark/test/FetcherTest.scala
@@ -512,7 +512,8 @@ class FetcherTest extends TestCase {
                            endDs: String,
                            namespace: String,
                            consistencyCheck: Boolean,
-                           dropDsOnWrite: Boolean): Unit = {
+                           dropDsOnWrite: Boolean,
+                           misTypeKeys: Boolean = true): Unit = {
     implicit val executionContext: ExecutionContext = ExecutionContext.fromExecutor(Executors.newFixedThreadPool(1))
     val spark: SparkSession = SparkSessionBuilder.build(sessionName + "_" + Random.alphanumeric.take(6).mkString, local = true)
     val tableUtils = TableUtils(spark)
@@ -564,7 +565,7 @@ class FetcherTest extends TestCase {
       val lagMs = -100000
       val laggedRequests = buildRequests(lagMs)
       val laggedResponseDf =
-        FetcherTestUtil.joinResponses(spark, laggedRequests, mockApi, samplePercent = 5, logToHive = true)._2
+        FetcherTestUtil.joinResponses(spark, laggedRequests, mockApi, samplePercent = 5, logToHive = true, misTypeKeys = misTypeKeys)._2
       val correctedLaggedResponse = laggedResponseDf
         .withColumn("ts_lagged", laggedResponseDf.col("ts_millis") + lagMs)
         .withColumn("ts_millis", col("ts_lagged"))
@@ -595,13 +596,13 @@ class FetcherTest extends TestCase {
           |""".stripMargin)
     }
     // benchmark
-    FetcherTestUtil.joinResponses(spark, requests, mockApi, runCount = 10, useJavaFetcher = true)
-    FetcherTestUtil.joinResponses(spark, requests, mockApi, runCount = 10)
+    FetcherTestUtil.joinResponses(spark, requests, mockApi, runCount = 10, useJavaFetcher = true, misTypeKeys = misTypeKeys)
+    FetcherTestUtil.joinResponses(spark, requests, mockApi, runCount = 10, misTypeKeys = misTypeKeys)
 
     // comparison
     val columns = endDsExpected.schema.fields.map(_.name)
     val responseRows: Seq[Row] =
-      FetcherTestUtil.joinResponses(spark, requests, mockApi, useJavaFetcher = true, debug = true)._1.map { res =>
+      FetcherTestUtil.joinResponses(spark, requests, mockApi, useJavaFetcher = true, debug = true, misTypeKeys = misTypeKeys)._1.map { res =>
         val all: Map[String, AnyRef] =
           res.request.keys ++
             res.values.get ++
@@ -657,18 +658,18 @@ class FetcherTest extends TestCase {
     )
     joinConf.setDerivations(derivations.toJava)
 
-    compareTemporalFetch(joinConf, "2021-04-10", namespace, consistencyCheck = false, dropDsOnWrite = true)
+    compareTemporalFetch(joinConf, "2021-04-10", namespace, consistencyCheck = false, dropDsOnWrite = true, misTypeKeys = false)
   }
 
   def testTemporalFetchJoinDerivationRenameOnly(): Unit = {
-    val namespace = "derivation_fetch"
+    val namespace = "derivation_fetch_rename_only"
     val joinConf = generateMutationData(namespace)
     val derivations = Seq(Builders.Derivation(name = "*", expression = "*"),
       Builders.Derivation(name = "listing_id_renamed", expression = "listing_id")
     )
     joinConf.setDerivations(derivations.toJava)
 
-    compareTemporalFetch(joinConf, "2021-04-10", namespace, consistencyCheck = false, dropDsOnWrite = true)
+    compareTemporalFetch(joinConf, "2021-04-10", namespace, consistencyCheck = false, dropDsOnWrite = true, misTypeKeys = false)
   }
 
 
@@ -724,7 +725,8 @@ object FetcherTestUtil {
                     runCount: Int = 1,
                     samplePercent: Double = -1,
                     logToHive: Boolean = false,
-                    debug: Boolean = false)(implicit ec: ExecutionContext): (List[Response], DataFrame) = {
+                    debug: Boolean = false,
+                    misTypeKeys: Boolean = true)(implicit ec: ExecutionContext): (List[Response], DataFrame) = {
     val chunkSize = 100
     @transient lazy val fetcher = mockApi.buildFetcher(debug)
     @transient lazy val javaFetcher = mockApi.buildJavaFetcher()
@@ -736,7 +738,15 @@ object FetcherTestUtil {
       val result = requests.iterator
         .grouped(chunkSize)
         .map { oldReqs =>
-          val r = oldReqs
+          // deliberately mis-type a few keys
+          val r = if (misTypeKeys) {
+            oldReqs
+              .map(r =>
+                r.copy(keys = r.keys.mapValues { v =>
+                  if (v.isInstanceOf[java.lang.Long]) v.toString else v
+                }.toMap))
+          } else oldReqs
+
           val responses = if (useJavaFetcher) {
             // Converting to java request and using the toScalaRequest functionality to test conversion
             val convertedJavaRequests = r.map(new JavaRequest(_)).toJava
@@ -753,7 +763,11 @@ object FetcherTestUtil {
             fetcher.fetchJoin(r)
           }
 
-          System.currentTimeMillis() -> responses
+          // fix mis-typed keys in the request
+          val fixedResponses = if (misTypeKeys) {
+            responses.map(resps => resps.zip(oldReqs).map { case (resp, req) => resp.copy(request = req) })
+          } else responses
+          System.currentTimeMillis() -> fixedResponses
         }
         .flatMap {
           case (start, future) =>