diff --git a/spark/src/main/scala/ai/chronon/spark/GroupBy.scala b/spark/src/main/scala/ai/chronon/spark/GroupBy.scala
index 8cee7bc86f..9c2c1f0e31 100644
--- a/spark/src/main/scala/ai/chronon/spark/GroupBy.scala
+++ b/spark/src/main/scala/ai/chronon/spark/GroupBy.scala
@@ -686,8 +686,10 @@ object GroupBy {
                       overrideStartPartition: Option[String] = None,
                       skipFirstHole: Boolean = true): Unit = {
     assert(
-      groupByConf.backfillStartDate != null,
-      s"GroupBy:${groupByConf.metaData.name} has null backfillStartDate. This needs to be set for offline backfilling.")
+      groupByConf.backfillStartDate != null || overrideStartPartition != null,
+      s"GroupBy:${groupByConf.metaData.name} has null backfillStartDate or overrideStartPartition." +
+        s" This needs to be set for offline backfilling."
+    )
     groupByConf.setups.foreach(tableUtils.sql)
     val overrideStart = overrideStartPartition.getOrElse(groupByConf.backfillStartDate)
     val outputTable = groupByConf.metaData.outputTable