diff --git a/test/api_integration/apis/saved_objects/delete_unknown_types.ts b/test/api_integration/apis/saved_objects/delete_unknown_types.ts
index 93d38f50a8080..476995347f211 100644
--- a/test/api_integration/apis/saved_objects/delete_unknown_types.ts
+++ b/test/api_integration/apis/saved_objects/delete_unknown_types.ts
@@ -7,7 +7,7 @@
  */
 
 import expect from '@kbn/expect';
-import { FtrProviderContext } from '../../ftr_provider_context';
+import type { FtrProviderContext } from '../../ftr_provider_context';
 
 const delay = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));
 
@@ -16,10 +16,10 @@ export default function ({ getService }: FtrProviderContext) {
   const esArchiver = getService('esArchiver');
   const es = getService('es');
 
-  // FLAKY: https://github.com/elastic/kibana/issues/164387
-  describe.skip('/deprecations/_delete_unknown_types', () => {
+  describe('/deprecations/_delete_unknown_types', () => {
     before(async () => {
-      await esArchiver.emptyKibanaIndex();
+      // we are injecting unknown types in this archive, so we need to relax the mappings restrictions
+      await es.indices.putMapping({ index: '.kibana', body: { dynamic: true } });
       await esArchiver.load(
         'test/api_integration/fixtures/es_archiver/saved_objects/delete_unknown_types'
       );
diff --git a/test/api_integration/fixtures/es_archiver/saved_objects/delete_unknown_types/mappings.json b/test/api_integration/fixtures/es_archiver/saved_objects/delete_unknown_types/mappings.json
deleted file mode 100644
index f745e0f69c5d3..0000000000000
--- a/test/api_integration/fixtures/es_archiver/saved_objects/delete_unknown_types/mappings.json
+++ /dev/null
@@ -1,530 +0,0 @@
-{
-  "type": "index",
-  "value": {
-    "aliases": {
-      ".kibana_$KIBANA_PACKAGE_VERSION": {},
-      ".kibana": {}
-    },
-    "index": ".kibana_$KIBANA_PACKAGE_VERSION_001",
-    "mappings": {
-      "_meta": {
-        "migrationMappingPropertyHashes": {
-          "application_usage_daily": "43b8830d5d0df85a6823d290885fc9fd",
-          "application_usage_totals": "3d1b76c39bfb2cc8296b024d73854724",
-          "application_usage_transactional": "3d1b76c39bfb2cc8296b024d73854724",
-          "config": "c63748b75f39d0c54de12d12c1ccbc20",
-          "core-usage-stats": "3d1b76c39bfb2cc8296b024d73854724",
-          "coreMigrationVersion": "2f4316de49999235636386fe51dc06c1",
-          "dashboard": "40554caf09725935e2c02e02563a2d07",
-          "index-pattern": "45915a1ad866812242df474eb0479052",
-          "kql-telemetry": "d12a98a6f19a2d273696597547e064ee",
-          "legacy-url-alias": "6155300fd11a00e23d5cbaa39f0fce0a",
-          "migrationVersion": "4a1746014a75ade3a714e1db5763276f",
-          "namespace": "2f4316de49999235636386fe51dc06c1",
-          "namespaces": "2f4316de49999235636386fe51dc06c1",
-          "originId": "2f4316de49999235636386fe51dc06c1",
-          "query": "11aaeb7f5f7fa5bb43f25e18ce26e7d9",
-          "references": "7997cf5a56cc02bdc9c93361bde732b0",
-          "sample-data-telemetry": "7d3cfeb915303c9641c59681967ffeb4",
-          "search": "db2c00e39b36f40930a3b9fc71c823e1",
-          "search-telemetry": "3d1b76c39bfb2cc8296b024d73854724",
-          "telemetry": "36a616f7026dfa617d6655df850fe16d",
-          "timelion-sheet": "9a2a2748877c7a7b582fef201ab1d4cf",
-          "type": "2f4316de49999235636386fe51dc06c1",
-          "ui-counter": "0d409297dc5ebe1e3a1da691c6ee32e3",
-          "ui-metric": "0d409297dc5ebe1e3a1da691c6ee32e3",
-          "updated_at": "00da57df13e94e9d98437d13ace4bfe0",
-          "url": "c7f66a0df8b1b52f17c28c4adb111105",
-          "usage-counters": "8cc260bdceffec4ffc3ad165c97dc1b4",
-          "visualization": "f819cf6636b75c9e76ba733a0c6ef355"
-        }
-      },
-      "dynamic": "strict",
-      "properties": {
-        "application_usage_daily": {
-          "dynamic": "false",
-          "properties": {
-            "timestamp": {
-              "type": "date"
-            }
-          }
-        },
-        "application_usage_totals": {
-          "dynamic": "false",
-          "type": "object"
-        },
-        "application_usage_transactional": {
-          "dynamic": "false",
-          "type": "object"
-        },
-        "config": {
-          "dynamic": "false",
-          "properties": {
-            "buildNum": {
-              "type": "keyword"
-            }
-          }
-        },
-        "unknown-type": {
-          "dynamic": "false",
-          "properties": {
-            "foo": {
-              "type": "keyword"
-            }
-          }
-        },
-        "unknown-shareable-type": {
-          "dynamic": "false",
-          "properties": {
-            "foo": {
-              "type": "keyword"
-            }
-          }
-        },
-        "core-usage-stats": {
-          "dynamic": "false",
-          "type": "object"
-        },
-        "coreMigrationVersion": {
-          "type": "keyword"
-        },
-        "dashboard": {
-          "properties": {
-            "description": {
-              "type": "text"
-            },
-            "hits": {
-              "doc_values": false,
-              "index": false,
-              "type": "integer"
-            },
-            "kibanaSavedObjectMeta": {
-              "properties": {
-                "searchSourceJSON": {
-                  "index": false,
-                  "type": "text"
-                }
-              }
-            },
-            "optionsJSON": {
-              "index": false,
-              "type": "text"
-            },
-            "panelsJSON": {
-              "index": false,
-              "type": "text"
-            },
-            "refreshInterval": {
-              "properties": {
-                "display": {
-                  "doc_values": false,
-                  "index": false,
-                  "type": "keyword"
-                },
-                "pause": {
-                  "doc_values": false,
-                  "index": false,
-                  "type": "boolean"
-                },
-                "section": {
-                  "doc_values": false,
-                  "index": false,
-                  "type": "integer"
-                },
-                "value": {
-                  "doc_values": false,
-                  "index": false,
-                  "type": "integer"
-                }
-              }
-            },
-            "timeFrom": {
-              "doc_values": false,
-              "index": false,
-              "type": "keyword"
-            },
-            "timeRestore": {
-              "doc_values": false,
-              "index": false,
-              "type": "boolean"
-            },
-            "timeTo": {
-              "doc_values": false,
-              "index": false,
-              "type": "keyword"
-            },
-            "title": {
-              "type": "text"
-            },
-            "version": {
-              "type": "integer"
-            }
-          }
-        },
-        "index-pattern": {
-          "dynamic": "false",
-          "properties": {
-            "title": {
-              "type": "text"
-            },
-            "type": {
-              "type": "keyword"
-            }
-          }
-        },
-        "kql-telemetry": {
-          "properties": {
-            "optInCount": {
-              "type": "long"
-            },
-            "optOutCount": {
-              "type": "long"
-            }
-          }
-        },
-        "legacy-url-alias": {
-          "dynamic": "false",
-          "properties": {
-            "disabled": {
-              "type": "boolean"
-            },
-            "sourceId": {
-              "type": "keyword"
-            },
-            "targetType": {
-              "type": "keyword"
-            }
-          }
-        },
-        "migrationVersion": {
-          "dynamic": "true",
-          "properties": {
-            "config": {
-              "fields": {
-                "keyword": {
-                  "ignore_above": 256,
-                  "type": "keyword"
-                }
-              },
-              "type": "text"
-            },
-            "dashboard": {
-              "fields": {
-                "keyword": {
-                  "ignore_above": 256,
-                  "type": "keyword"
-                }
-              },
-              "type": "text"
-            },
-            "index-pattern": {
-              "fields": {
-                "keyword": {
-                  "ignore_above": 256,
-                  "type": "keyword"
-                }
-              },
-              "type": "text"
-            },
-            "search": {
-              "fields": {
-                "keyword": {
-                  "ignore_above": 256,
-                  "type": "keyword"
-                }
-              },
-              "type": "text"
-            },
-            "visualization": {
-              "fields": {
-                "keyword": {
-                  "ignore_above": 256,
-                  "type": "keyword"
-                }
-              },
-              "type": "text"
-            }
-          }
-        },
-        "namespace": {
-          "type": "keyword"
-        },
-        "namespaces": {
-          "type": "keyword"
-        },
-        "originId": {
-          "type": "keyword"
-        },
-        "query": {
-          "properties": {
-            "description": {
-              "type": "text"
-            },
-            "filters": {
-              "enabled": false,
-              "type": "object"
-            },
-            "query": {
-              "properties": {
-                "language": {
-                  "type": "keyword"
-                },
-                "query": {
-                  "index": false,
-                  "type": "keyword"
-                }
-              }
-            },
-            "timefilter": {
-              "enabled": false,
-              "type": "object"
-            },
-            "title": {
-              "type": "text"
-            }
-          }
-        },
-        "references": {
-          "properties": {
-            "id": {
-              "type": "keyword"
-            },
-            "name": {
-              "type": "keyword"
-            },
-            "type": {
-              "type": "keyword"
-            }
-          },
-          "type": "nested"
-        },
-        "sample-data-telemetry": {
-          "properties": {
-            "installCount": {
-              "type": "long"
-            },
-            "unInstallCount": {
-              "type": "long"
-            }
-          }
-        },
-        "search": {
-          "properties": {
-            "columns": {
-              "doc_values": false,
-              "index": false,
-              "type": "keyword"
-            },
-            "description": {
-              "type": "text"
-            },
-            "grid": {
-              "enabled": false,
-              "type": "object"
-            },
-            "hideChart": {
-              "doc_values": false,
-              "index": false,
-              "type": "boolean"
-            },
-            "hits": {
-              "doc_values": false,
-              "index": false,
-              "type": "integer"
-            },
-            "kibanaSavedObjectMeta": {
-              "properties": {
-                "searchSourceJSON": {
-                  "index": false,
-                  "type": "text"
-                }
-              }
-            },
-            "sort": {
-              "doc_values": false,
-              "index": false,
-              "type": "keyword"
-            },
-            "title": {
-              "type": "text"
-            },
-            "version": {
-              "type": "integer"
-            }
-          }
-        },
-        "search-telemetry": {
-          "dynamic": "false",
-          "type": "object"
-        },
-        "server": {
-          "dynamic": "false",
-          "type": "object"
-        },
-        "telemetry": {
-          "properties": {
-            "allowChangingOptInStatus": {
-              "type": "boolean"
-            },
-            "enabled": {
-              "type": "boolean"
-            },
-            "lastReported": {
-              "type": "date"
-            },
-            "lastVersionChecked": {
-              "type": "keyword"
-            },
-            "reportFailureCount": {
-              "type": "integer"
-            },
-            "reportFailureVersion": {
-              "type": "keyword"
-            },
-            "sendUsageFrom": {
-              "type": "keyword"
-            },
-            "userHasSeenNotice": {
-              "type": "boolean"
-            }
-          }
-        },
-        "timelion-sheet": {
-          "properties": {
-            "description": {
-              "type": "text"
-            },
-            "hits": {
-              "type": "integer"
-            },
-            "kibanaSavedObjectMeta": {
-              "properties": {
-                "searchSourceJSON": {
-                  "type": "text"
-                }
-              }
-            },
-            "timelion_chart_height": {
-              "type": "integer"
-            },
-            "timelion_columns": {
-              "type": "integer"
-            },
-            "timelion_interval": {
-              "type": "keyword"
-            },
-            "timelion_other_interval": {
-              "type": "keyword"
-            },
-            "timelion_rows": {
-              "type": "integer"
-            },
-            "timelion_sheet": {
-              "type": "text"
-            },
-            "title": {
-              "type": "text"
-            },
-            "version": {
-              "type": "integer"
-            }
-          }
-        },
-        "type": {
-          "type": "keyword"
-        },
-        "ui-counter": {
-          "properties": {
-            "count": {
-              "type": "integer"
-            }
-          }
-        },
-        "ui-metric": {
-          "properties": {
-            "count": {
-              "type": "integer"
-            }
-          }
-        },
-        "updated_at": {
-          "type": "date"
-        },
-        "url": {
-          "properties": {
-            "accessCount": {
-              "type": "long"
-            },
-            "accessDate": {
-              "type": "date"
-            },
-            "createDate": {
-              "type": "date"
-            },
-            "url": {
-              "fields": {
-                "keyword": {
-                  "ignore_above": 2048,
-                  "type": "keyword"
-                }
-              },
-              "type": "text"
-            }
-          }
-        },
-        "usage-counters": {
-          "dynamic": "false",
-          "properties": {
-            "domainId": {
-              "type": "keyword"
-            }
-          }
-        },
-        "visualization": {
-          "properties": {
-            "description": {
-              "type": "text"
-            },
-            "kibanaSavedObjectMeta": {
-              "properties": {
-                "searchSourceJSON": {
-                  "index": false,
-                  "type": "text"
-                }
-              }
-            },
-            "savedSearchRefName": {
-              "doc_values": false,
-              "index": false,
-              "type": "keyword"
-            },
-            "title": {
-              "type": "text"
-            },
-            "uiStateJSON": {
-              "index": false,
-              "type": "text"
-            },
-            "version": {
-              "type": "integer"
-            },
-            "visState": {
-              "index": false,
-              "type": "text"
-            }
-          }
-        }
-      }
-    },
-    "settings": {
-      "index": {
-        "auto_expand_replicas": "0-1",
-        "number_of_replicas": "0",
-        "number_of_shards": "1",
-        "priority": "10",
-        "refresh_interval": "1s",
-        "routing_partition_size": "1"
-      }
-    }
-  }
-}