diff --git a/src/main/kotlin/com/github/thake/logminer/kafka/connect/logminer/TransactionConsolidator.kt b/src/main/kotlin/com/github/thake/logminer/kafka/connect/logminer/TransactionConsolidator.kt
index cda20f6..8d6e5ae 100644
--- a/src/main/kotlin/com/github/thake/logminer/kafka/connect/logminer/TransactionConsolidator.kt
+++ b/src/main/kotlin/com/github/thake/logminer/kafka/connect/logminer/TransactionConsolidator.kt
@@ -111,6 +111,6 @@ class TransactionConsolidator(
     }
 
     private fun refreshMinOpenScn() {
-        minOpenTransaction = openTransactions.values.minBy { it.minScn }
+        minOpenTransaction = openTransactions.values.minByOrNull { it.minScn }
     }
 }
\ No newline at end of file