diff --git a/output/schema/schema.json b/output/schema/schema.json
index c2d2c3ae51..87bb2d4091 100644
--- a/output/schema/schema.json
+++ b/output/schema/schema.json
@@ -165157,10 +165157,13 @@
           "name": "initial_master_nodes",
           "required": false,
           "type": {
-            "kind": "instance_of",
-            "type": {
-              "name": "string",
-              "namespace": "_builtins"
+            "kind": "array_of",
+            "value": {
+              "kind": "instance_of",
+              "type": {
+                "name": "string",
+                "namespace": "_builtins"
+              }
             }
           }
         },
diff --git a/output/typescript/types.ts b/output/typescript/types.ts
index c3230952a3..4b3f3e50e7 100644
--- a/output/typescript/types.ts
+++ b/output/typescript/types.ts
@@ -15406,7 +15406,7 @@ export interface NodesInfoNodeInfoSettingsCluster {
   name: Name
   routing?: IndicesIndexRouting
   election: NodesInfoNodeInfoSettingsClusterElection
-  initial_master_nodes?: string
+  initial_master_nodes?: string[]
   deprecation_indexing?: NodesInfoDeprecationIndexing
 }
 
diff --git a/specification/nodes/info/types.ts b/specification/nodes/info/types.ts
index 9ac37e208c..d31490a810 100644
--- a/specification/nodes/info/types.ts
+++ b/specification/nodes/info/types.ts
@@ -132,7 +132,7 @@ export class NodeInfoSettingsCluster {
   name: Name
   routing?: IndexRouting
   election: NodeInfoSettingsClusterElection
-  initial_master_nodes?: string
+  initial_master_nodes?: string[]
   /**
    * @availability stack since=7.16.0
    * @availability serverless