diff --git a/src/main/java/com/amazonaws/services/kinesis/clientlibrary/lib/worker/PrefetchGetRecordsCache.java b/src/main/java/com/amazonaws/services/kinesis/clientlibrary/lib/worker/PrefetchGetRecordsCache.java
index f5d82dab..979c5b1a 100644
--- a/src/main/java/com/amazonaws/services/kinesis/clientlibrary/lib/worker/PrefetchGetRecordsCache.java
+++ b/src/main/java/com/amazonaws/services/kinesis/clientlibrary/lib/worker/PrefetchGetRecordsCache.java
@@ -137,7 +137,7 @@ public class PrefetchGetRecordsCache implements GetRecordsCache {
             return result.getRecords().stream().mapToLong(record -> record.getData().array().length).sum();
         }
         
-        public boolean shouldGetNewRecords() {
+        public synchronized boolean shouldGetNewRecords() {
             return size < maxRecordsCount && byteSize < maxByteSize;
         }
     }
diff --git a/src/test/java/com/amazonaws/services/kinesis/clientlibrary/lib/worker/BlockingGetRecordsCacheTest.java b/src/test/java/com/amazonaws/services/kinesis/clientlibrary/lib/worker/BlockingGetRecordsCacheTest.java
index 50abd6f8..0636baea 100644
--- a/src/test/java/com/amazonaws/services/kinesis/clientlibrary/lib/worker/BlockingGetRecordsCacheTest.java
+++ b/src/test/java/com/amazonaws/services/kinesis/clientlibrary/lib/worker/BlockingGetRecordsCacheTest.java
@@ -51,11 +51,11 @@ public class BlockingGetRecordsCacheTest {
 
     @Before
     public void setup() {
-        when(getRecordsRetrievalStrategy.getRecords(eq(MAX_RECORDS_PER_COUNT))).thenReturn(getRecordsResult);
-        when(getRecordsResult.getRecords()).thenReturn(records);
-
         records = new ArrayList<>();
         blockingGetRecordsCache = new BlockingGetRecordsCache(MAX_RECORDS_PER_COUNT, getRecordsRetrievalStrategy);
+
+        when(getRecordsRetrievalStrategy.getRecords(eq(MAX_RECORDS_PER_COUNT))).thenReturn(getRecordsResult);
+        when(getRecordsResult.getRecords()).thenReturn(records);
     }
 
     @Test