diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
index 5e95073209c71..b4911009a5b5f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
@@ -139,6 +139,7 @@ public void setupSuiteScopeCluster() throws Exception {
                 .get();
         }
         client().admin().indices().refresh(new RefreshRequest("test")).get();
+        indexRandomForMultipleSlices("test", "idx_unmapped", "idx_unmapped_author");
     }
 
     public void testIssue10719() throws Exception {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NaNSortingIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NaNSortingIT.java
index 1ef2c0e8db8c7..79ba661b8b332 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NaNSortingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NaNSortingIT.java
@@ -173,6 +173,7 @@ public void setupSuiteScopeCluster() throws Exception {
         }
         refresh();
         ensureSearchable();
+        indexRandomForMultipleSlices("idx", "idx");
     }
 
     private void assertCorrectlySorted(Terms terms, boolean asc, SubAggregation agg) {