diff --git a/server/src/main/java/org/elasticsearch/cluster/metadata/RepositoriesMetaData.java b/server/src/main/java/org/elasticsearch/cluster/metadata/RepositoriesMetaData.java
index 6aa2d83fa8d..7a0b9285896 100644
--- a/server/src/main/java/org/elasticsearch/cluster/metadata/RepositoriesMetaData.java
+++ b/server/src/main/java/org/elasticsearch/cluster/metadata/RepositoriesMetaData.java
@@ -50,8 +50,8 @@ public class RepositoriesMetaData extends AbstractNamedDiffable<Custom> implemen
      *
      * @param repositories list of repositories
      */
-    public RepositoriesMetaData(RepositoryMetaData... repositories) {
-        this.repositories = Arrays.asList(repositories);
+    public RepositoriesMetaData(List<RepositoryMetaData> repositories) {
+        this.repositories = repositories;
     }
 
     /**
@@ -164,7 +164,7 @@ public class RepositoriesMetaData extends AbstractNamedDiffable<Custom> implemen
                 throw new ElasticsearchParseException("failed to parse repositories");
             }
         }
-        return new RepositoriesMetaData(repository.toArray(new RepositoryMetaData[repository.size()]));
+        return new RepositoriesMetaData(repository);
     }
 
     /**
diff --git a/server/src/main/java/org/elasticsearch/repositories/RepositoriesService.java b/server/src/main/java/org/elasticsearch/repositories/RepositoriesService.java
index 577ccc78de7..636e108468e 100644
--- a/server/src/main/java/org/elasticsearch/repositories/RepositoriesService.java
+++ b/server/src/main/java/org/elasticsearch/repositories/RepositoriesService.java
@@ -114,7 +114,8 @@ public class RepositoriesService extends AbstractComponent implements ClusterSta
                 RepositoriesMetaData repositories = metaData.custom(RepositoriesMetaData.TYPE);
                 if (repositories == null) {
                     logger.info("put repository [{}]", request.name);
-                    repositories = new RepositoriesMetaData(new RepositoryMetaData(request.name, request.type, request.settings));
+                    repositories = new RepositoriesMetaData(
+                        Collections.singletonList(new RepositoryMetaData(request.name, request.type, request.settings)));
                 } else {
                     boolean found = false;
                     List<RepositoryMetaData> repositoriesMetaData = new ArrayList<>(repositories.repositories().size() + 1);
@@ -133,7 +134,7 @@ public class RepositoriesService extends AbstractComponent implements ClusterSta
                     } else {
                         logger.info("update repository [{}]", request.name);
                     }
-                    repositories = new RepositoriesMetaData(repositoriesMetaData.toArray(new RepositoryMetaData[repositoriesMetaData.size()]));
+                    repositories = new RepositoriesMetaData(repositoriesMetaData);
                 }
                 mdBuilder.putCustom(RepositoriesMetaData.TYPE, repositories);
                 return ClusterState.builder(currentState).metaData(mdBuilder).build();
@@ -185,7 +186,7 @@ public class RepositoriesService extends AbstractComponent implements ClusterSta
                         }
                     }
                     if (changed) {
-                        repositories = new RepositoriesMetaData(repositoriesMetaData.toArray(new RepositoryMetaData[repositoriesMetaData.size()]));
+                        repositories = new RepositoriesMetaData(repositoriesMetaData);
                         mdBuilder.putCustom(RepositoriesMetaData.TYPE, repositories);
                         return ClusterState.builder(currentState).metaData(mdBuilder).build();
                     }
diff --git a/server/src/test/java/org/elasticsearch/cluster/ClusterStateDiffIT.java b/server/src/test/java/org/elasticsearch/cluster/ClusterStateDiffIT.java
index 29e3080bfe1..a5d865a2741 100644
--- a/server/src/test/java/org/elasticsearch/cluster/ClusterStateDiffIT.java
+++ b/server/src/test/java/org/elasticsearch/cluster/ClusterStateDiffIT.java
@@ -640,7 +640,7 @@ public class ClusterStateDiffIT extends ESIntegTestCase {
             @Override
             public MetaData.Custom randomCreate(String name) {
                 if (randomBoolean()) {
-                    return new RepositoriesMetaData();
+                    return new RepositoriesMetaData(Collections.emptyList());
                 } else {
                     return IndexGraveyardTests.createRandom();
                 }
diff --git a/server/src/test/java/org/elasticsearch/snapshots/RepositoriesMetaDataSerializationTests.java b/server/src/test/java/org/elasticsearch/snapshots/RepositoriesMetaDataSerializationTests.java
index dc0c7b55c6d..7627dafa5a9 100644
--- a/server/src/test/java/org/elasticsearch/snapshots/RepositoriesMetaDataSerializationTests.java
+++ b/server/src/test/java/org/elasticsearch/snapshots/RepositoriesMetaDataSerializationTests.java
@@ -45,7 +45,7 @@ public class RepositoriesMetaDataSerializationTests extends AbstractDiffableSeri
             entries.add(new RepositoryMetaData(randomAlphaOfLength(10), randomAlphaOfLength(10), randomSettings()));
         }
         entries.sort(Comparator.comparing(RepositoryMetaData::name));
-        return new RepositoriesMetaData(entries.toArray(new RepositoryMetaData[entries.size()]));
+        return new RepositoriesMetaData(entries);
     }
 
     @Override
@@ -62,7 +62,7 @@ public class RepositoriesMetaDataSerializationTests extends AbstractDiffableSeri
         } else {
             entries.remove(randomIntBetween(0, entries.size() - 1));
         }
-        return new RepositoriesMetaData(entries.toArray(new RepositoryMetaData[entries.size()]));
+        return new RepositoriesMetaData(entries);
     }
 
     public Settings randomSettings() {
@@ -94,7 +94,7 @@ public class RepositoriesMetaDataSerializationTests extends AbstractDiffableSeri
                 repos.add(new RepositoryMetaData(randomAlphaOfLength(10), randomAlphaOfLength(10), randomSettings()));
             }
         }
-        return new RepositoriesMetaData(repos.toArray(new RepositoryMetaData[repos.size()]));
+        return new RepositoriesMetaData(repos);
     }
 
     @Override
@@ -114,7 +114,7 @@ public class RepositoriesMetaDataSerializationTests extends AbstractDiffableSeri
         assertEquals(XContentParser.Token.END_OBJECT, parser.currentToken());
         List<RepositoryMetaData> repos = repositoriesMetaData.repositories();
         repos.sort(Comparator.comparing(RepositoryMetaData::name));
-        return new RepositoriesMetaData(repos.toArray(new RepositoryMetaData[repos.size()]));
+        return new RepositoriesMetaData(repos);
     }
 
 }
diff --git a/x-pack/plugin/core/src/test/java/org/elasticsearch/license/LicensesMetaDataSerializationTests.java b/x-pack/plugin/core/src/test/java/org/elasticsearch/license/LicensesMetaDataSerializationTests.java
index b85a3480fa7..f3ed04ed22d 100644
--- a/x-pack/plugin/core/src/test/java/org/elasticsearch/license/LicensesMetaDataSerializationTests.java
+++ b/x-pack/plugin/core/src/test/java/org/elasticsearch/license/LicensesMetaDataSerializationTests.java
@@ -64,7 +64,7 @@ public class LicensesMetaDataSerializationTests extends ESTestCase {
         License license = TestUtils.generateSignedLicense(TimeValue.timeValueHours(2));
         LicensesMetaData licensesMetaData = new LicensesMetaData(license, Version.CURRENT);
         RepositoryMetaData repositoryMetaData = new RepositoryMetaData("repo", "fs", Settings.EMPTY);
-        RepositoriesMetaData repositoriesMetaData = new RepositoriesMetaData(repositoryMetaData);
+        RepositoriesMetaData repositoriesMetaData = new RepositoriesMetaData(Collections.singletonList(repositoryMetaData));
         final MetaData.Builder metaDataBuilder = MetaData.builder();
         if (randomBoolean()) { // random order of insertion
             metaDataBuilder.putCustom(licensesMetaData.getWriteableName(), licensesMetaData);
diff --git a/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/WatcherMetaDataSerializationTests.java b/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/WatcherMetaDataSerializationTests.java
index 50a7fec4749..0556b8535e4 100644
--- a/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/WatcherMetaDataSerializationTests.java
+++ b/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/WatcherMetaDataSerializationTests.java
@@ -47,7 +47,7 @@ public class WatcherMetaDataSerializationTests extends ESTestCase {
         boolean manuallyStopped = randomBoolean();
         WatcherMetaData watcherMetaData = new WatcherMetaData(manuallyStopped);
         RepositoryMetaData repositoryMetaData = new RepositoryMetaData("repo", "fs", Settings.EMPTY);
-        RepositoriesMetaData repositoriesMetaData = new RepositoriesMetaData(repositoryMetaData);
+        RepositoriesMetaData repositoriesMetaData = new RepositoriesMetaData(Collections.singletonList(repositoryMetaData));
         final MetaData.Builder metaDataBuilder = MetaData.builder();
         if (randomBoolean()) { // random order of insertion
             metaDataBuilder.putCustom(watcherMetaData.getWriteableName(), watcherMetaData);