diff --git a/server/src/main/java/io/druid/client/CachingClusteredClient.java b/server/src/main/java/io/druid/client/CachingClusteredClient.java
index 28135a8bb55cf3ee6d58b8ce0e06a8c9ba60beb2..ff374c3c4b1bb7f895d6ec75171be8a039023adf 100644
--- a/server/src/main/java/io/druid/client/CachingClusteredClient.java
+++ b/server/src/main/java/io/druid/client/CachingClusteredClient.java
@@ -183,7 +183,8 @@ public class CachingClusteredClient<T> implements QueryRunner<T>
     }
 
     if (queryCacheKey != null) {
-      Map<Pair<ServerSelector, SegmentDescriptor>, Cache.NamedKey> cacheKeys = Maps.newHashMap();
+      // cache keys must preserve segment ordering, in order for shards to always be combined in the same order
+      Map<Pair<ServerSelector, SegmentDescriptor>, Cache.NamedKey> cacheKeys = Maps.newLinkedHashMap();
       for (Pair<ServerSelector, SegmentDescriptor> segment : segments) {
         final Cache.NamedKey segmentCacheKey = CacheUtil.computeSegmentCacheKey(
             segment.lhs.getSegment().getIdentifier(),