diff --git a/extensions-core/kafka-extraction-namespace/src/test/java/io/druid/query/lookup/KafkaLookupExtractorFactoryTest.java b/extensions-core/kafka-extraction-namespace/src/test/java/io/druid/query/lookup/KafkaLookupExtractorFactoryTest.java
index e2fe7d6e2676..13d7f191651c 100644
--- a/extensions-core/kafka-extraction-namespace/src/test/java/io/druid/query/lookup/KafkaLookupExtractorFactoryTest.java
+++ b/extensions-core/kafka-extraction-namespace/src/test/java/io/druid/query/lookup/KafkaLookupExtractorFactoryTest.java
@@ -26,6 +26,7 @@
 import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.primitives.Bytes;
 import io.druid.jackson.DefaultObjectMapper;
 import io.druid.java.util.common.StringUtils;
 import io.druid.server.lookup.namespace.cache.CacheHandler;
@@ -47,11 +48,12 @@
 import org.powermock.core.classloader.annotations.PrepareForTest;
 import org.powermock.modules.junit4.PowerMockRunner;
 
-import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
@@ -129,18 +131,15 @@ public void testCacheKeyScramblesOnNewData()
         TOPIC,
         DEFAULT_PROPERTIES
     );
-    factory.getMapRef().set(ImmutableMap.<String, String>of());
+    factory.getMapRef().set(ImmutableMap.of());
     final AtomicLong events = factory.getDoubleEventCount();
 
     final LookupExtractor extractor = factory.get();
 
-    final List<byte[]> byteArrays = new ArrayList<>(n);
+    final Set<List<Byte>> byteArrays = new HashSet<>(n);
     for (int i = 0; i < n; ++i) {
-      final byte[] myKey = extractor.getCacheKey();
-      // Not terribly efficient.. but who cares
-      for (byte[] byteArray : byteArrays) {
-        Assert.assertFalse(Arrays.equals(byteArray, myKey));
-      }
+      final List<Byte> myKey = Bytes.asList(extractor.getCacheKey());
+      Assert.assertFalse(byteArrays.contains(myKey));
       byteArrays.add(myKey);
       events.incrementAndGet();
     }
@@ -156,17 +155,14 @@ public void testCacheKeyScramblesDifferentStarts()
         TOPIC,
         DEFAULT_PROPERTIES
     );
-    factory.getMapRef().set(ImmutableMap.<String, String>of());
+    factory.getMapRef().set(ImmutableMap.of());
     final AtomicLong events = factory.getDoubleEventCount();
 
-    final List<byte[]> byteArrays = new ArrayList<>(n);
+    final Set<List<Byte>> byteArrays = new HashSet<>(n);
     for (int i = 0; i < n; ++i) {
       final LookupExtractor extractor = factory.get();
-      final byte[] myKey = extractor.getCacheKey();
-      // Not terribly efficient.. but who cares
-      for (byte[] byteArray : byteArrays) {
-        Assert.assertFalse(Arrays.equals(byteArray, myKey));
-      }
+      final List<Byte> myKey = Bytes.asList(extractor.getCacheKey());
+      Assert.assertFalse(byteArrays.contains(myKey));
       byteArrays.add(myKey);
       events.incrementAndGet();
     }