diff --git a/server/src/main/java/org/elasticsearch/cluster/metadata/IndexMetaData.java b/server/src/main/java/org/elasticsearch/cluster/metadata/IndexMetaData.java
index 06d5cd6f85d..9361c877d38 100644
--- a/server/src/main/java/org/elasticsearch/cluster/metadata/IndexMetaData.java
+++ b/server/src/main/java/org/elasticsearch/cluster/metadata/IndexMetaData.java
@@ -1111,7 +1111,7 @@ public class IndexMetaData implements Diffable<IndexMetaData>, ToXContentFragmen
             }
             int numberOfReplicas = maybeNumberOfReplicas;
             if (numberOfReplicas < 0) {
-                throw new IllegalArgumentException("must specify non-negative number of shards for index [" + index + "]");
+                throw new IllegalArgumentException("must specify non-negative number of replicas for index [" + index + "]");
             }
 
             int routingPartitionSize = INDEX_ROUTING_PARTITION_SIZE_SETTING.get(settings);