diff --git a/output/openapi/elasticsearch-openapi.json b/output/openapi/elasticsearch-openapi.json
index f4bd373de2..9b53c982ef 100644
--- a/output/openapi/elasticsearch-openapi.json
+++ b/output/openapi/elasticsearch-openapi.json
@@ -80650,6 +80650,12 @@
           },
           "_shards": {
             "$ref": "#/components/schemas/esql._types.EsqlShardInfo"
+          },
+          "failures": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/esql._types.EsqlShardFailure"
+            }
           }
         },
         "required": [
@@ -80681,12 +80687,6 @@
           },
           "failed": {
             "type": "number"
-          },
-          "failures": {
-            "type": "array",
-            "items": {
-              "$ref": "#/components/schemas/esql._types.EsqlShardFailure"
-            }
           }
         },
         "required": [
@@ -80697,10 +80697,18 @@
         "type": "object",
         "properties": {
           "shard": {
-            "$ref": "#/components/schemas/_types.Id"
+            "type": "number"
           },
           "index": {
-            "$ref": "#/components/schemas/_types.IndexName"
+            "oneOf": [
+              {
+                "$ref": "#/components/schemas/_types.IndexName"
+              },
+              {
+                "nullable": true,
+                "type": "string"
+              }
+            ]
           },
           "node": {
             "$ref": "#/components/schemas/_types.NodeId"
diff --git a/output/openapi/elasticsearch-serverless-openapi.json b/output/openapi/elasticsearch-serverless-openapi.json
index 2eb99359b7..26d08377e8 100644
--- a/output/openapi/elasticsearch-serverless-openapi.json
+++ b/output/openapi/elasticsearch-serverless-openapi.json
@@ -52321,6 +52321,12 @@
           },
           "_shards": {
             "$ref": "#/components/schemas/esql._types.EsqlShardInfo"
+          },
+          "failures": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/esql._types.EsqlShardFailure"
+            }
           }
         },
         "required": [
@@ -52352,12 +52358,6 @@
           },
           "failed": {
             "type": "number"
-          },
-          "failures": {
-            "type": "array",
-            "items": {
-              "$ref": "#/components/schemas/esql._types.EsqlShardFailure"
-            }
           }
         },
         "required": [
@@ -52368,10 +52368,18 @@
         "type": "object",
         "properties": {
           "shard": {
-            "$ref": "#/components/schemas/_types.Id"
+            "type": "number"
           },
           "index": {
-            "$ref": "#/components/schemas/_types.IndexName"
+            "oneOf": [
+              {
+                "$ref": "#/components/schemas/_types.IndexName"
+              },
+              {
+                "nullable": true,
+                "type": "string"
+              }
+            ]
           },
           "node": {
             "$ref": "#/components/schemas/_types.NodeId"
diff --git a/output/schema/schema.json b/output/schema/schema.json
index f58f37f0af..d1d711e831 100644
--- a/output/schema/schema.json
+++ b/output/schema/schema.json
@@ -128411,9 +128411,23 @@
               "namespace": "esql._types"
             }
           }
+        },
+        {
+          "name": "failures",
+          "required": false,
+          "type": {
+            "kind": "array_of",
+            "value": {
+              "kind": "instance_of",
+              "type": {
+                "name": "EsqlShardFailure",
+                "namespace": "esql._types"
+              }
+            }
+          }
         }
       ],
-      "specLocation": "esql/_types/EsqlResult.ts#L65-L70"
+      "specLocation": "esql/_types/EsqlResult.ts#L65-L71"
     },
     {
       "kind": "interface",
@@ -128536,7 +128550,7 @@
         "name": "EsqlClusterStatus",
         "namespace": "esql._types"
       },
-      "specLocation": "esql/_types/EsqlResult.ts#L72-L78"
+      "specLocation": "esql/_types/EsqlResult.ts#L73-L79"
     },
     {
       "kind": "interface",
@@ -128723,7 +128737,7 @@
           "type": {
             "kind": "instance_of",
             "type": {
-              "name": "Id",
+              "name": "integer",
               "namespace": "_types"
             }
           }
@@ -128732,11 +128746,23 @@
           "name": "index",
           "required": true,
           "type": {
-            "kind": "instance_of",
-            "type": {
-              "name": "IndexName",
-              "namespace": "_types"
-            }
+            "kind": "union_of",
+            "items": [
+              {
+                "kind": "instance_of",
+                "type": {
+                  "name": "IndexName",
+                  "namespace": "_types"
+                }
+              },
+              {
+                "kind": "instance_of",
+                "type": {
+                  "name": "null",
+                  "namespace": "_builtins"
+                }
+              }
+            ]
           }
         },
         {
@@ -128814,23 +128840,9 @@
               "namespace": "_types"
             }
           }
-        },
-        {
-          "name": "failures",
-          "required": false,
-          "type": {
-            "kind": "array_of",
-            "value": {
-              "kind": "instance_of",
-              "type": {
-                "name": "EsqlShardFailure",
-                "namespace": "esql._types"
-              }
-            }
-          }
         }
       ],
-      "specLocation": "esql/_types/EsqlResult.ts#L80-L86"
+      "specLocation": "esql/_types/EsqlResult.ts#L81-L86"
     },
     {
       "kind": "interface",
diff --git a/output/typescript/types.ts b/output/typescript/types.ts
index 0c5884d960..2f4cbc247f 100644
--- a/output/typescript/types.ts
+++ b/output/typescript/types.ts
@@ -10773,6 +10773,7 @@ export interface EsqlEsqlClusterDetails {
   indices: string
   took?: DurationValue<UnitMillis>
   _shards?: EsqlEsqlShardInfo
+  failures?: EsqlEsqlShardFailure[]
 }
 
 export interface EsqlEsqlClusterInfo {
@@ -10805,8 +10806,8 @@ export interface EsqlEsqlResult {
 }
 
 export interface EsqlEsqlShardFailure {
-  shard: Id
-  index: IndexName
+  shard: integer
+  index: IndexName | null
   node?: NodeId
   reason: ErrorCause
 }
@@ -10816,7 +10817,6 @@ export interface EsqlEsqlShardInfo {
   successful?: integer
   skipped?: integer
   failed?: integer
-  failures?: EsqlEsqlShardFailure[]
 }
 
 export interface EsqlTableValuesContainer {
diff --git a/specification/esql/_types/EsqlResult.ts b/specification/esql/_types/EsqlResult.ts
index 6a7cefa8bd..649e323d2b 100644
--- a/specification/esql/_types/EsqlResult.ts
+++ b/specification/esql/_types/EsqlResult.ts
@@ -17,7 +17,7 @@
  * under the License.
  */
 
-import { FieldValue, Id, IndexName, NodeId } from '@_types/common'
+import { FieldValue, IndexName, NodeId } from '@_types/common'
 import { ErrorCause } from '@_types/Errors'
 import { integer } from '@_types/Numeric'
 import { DurationValue, UnitMillis } from '@_types/Time'
@@ -67,6 +67,7 @@ export class EsqlClusterDetails {
   indices: string
   took?: DurationValue<UnitMillis>
   _shards?: EsqlShardInfo
+  failures?: EsqlShardFailure[]
 }
 
 export enum EsqlClusterStatus {
@@ -82,12 +83,11 @@ export class EsqlShardInfo {
   successful?: integer
   skipped?: integer
   failed?: integer
-  failures?: EsqlShardFailure[]
 }
 
 export class EsqlShardFailure {
-  shard: Id
-  index: IndexName
+  shard: integer
+  index: IndexName | null
   node?: NodeId
   reason: ErrorCause
 }