diff --git a/rest-api-spec/build.gradle b/rest-api-spec/build.gradle
index 3f9224b981a9d..2144dc1765af9 100644
--- a/rest-api-spec/build.gradle
+++ b/rest-api-spec/build.gradle
@@ -10,8 +10,3 @@ artifacts {
   restSpecs(new File(projectDir, "src/main/resources/rest-api-spec/api"))
   restTests(new File(projectDir, "src/main/resources/rest-api-spec/test"))
 }
-
-validateRestSpec {
-   ignore "cat.thread_pool.json"
-   ignore "indices.put_mapping.json"
-}
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/indices.put_mapping.json b/rest-api-spec/src/main/resources/rest-api-spec/api/indices.put_mapping.json
index deb7bb728f733..b93e423fcee4d 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/indices.put_mapping.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/indices.put_mapping.json
@@ -127,7 +127,7 @@
           }
         },
         {
-          "path":"{index}/_mappings",
+          "path":"/{index}/_mappings",
           "methods":[
             "PUT",
             "POST"
diff --git a/rest-api-spec/src/main/resources/schema.json b/rest-api-spec/src/main/resources/schema.json
index 6ae10164ee7b8..ae6759e704424 100644
--- a/rest-api-spec/src/main/resources/schema.json
+++ b/rest-api-spec/src/main/resources/schema.json
@@ -201,7 +201,7 @@
                     "type": "array",
                     "items": {
                         "type": "string",
-                        "pattern": "^[a-zA-Z_]+$"
+                        "pattern": "^\\d*|[a-zA-Z_]+$"
                     },
                     "title": "Valid options when type is an enum"
                 },