diff --git a/core/src/main/scala/kafka/consumer/ConsumerFetcherManager.scala b/core/src/main/scala/kafka/consumer/ConsumerFetcherManager.scala
index d1373c9..c6250dc 100644
--- a/core/src/main/scala/kafka/consumer/ConsumerFetcherManager.scala
+++ b/core/src/main/scala/kafka/consumer/ConsumerFetcherManager.scala
@@ -129,6 +129,10 @@ class ConsumerFetcherManager(private val consumerIdString: String,
     info("Stopping all fetchers")
     closeAllFetchers()
 
+    // no need to hold the lock for the following since leaderFindThread and all fetchers have been stopped
+    partitionMap = null
+    noLeaderPartitionSet.clear()
+
     info("All connections stopped")
   }