diff --git a/keyserver/src/utils/olm-utils.js b/keyserver/src/utils/olm-utils.js
index 45599ee5f..4d7c77826 100644
--- a/keyserver/src/utils/olm-utils.js
+++ b/keyserver/src/utils/olm-utils.js
@@ -1,18 +1,28 @@
 // @flow
 
 import invariant from 'invariant';
 
 import { importJSON } from './import-json.js';
 
 type OlmConfig = {
   +picklingKey: string,
   +pickledAccount: string,
 };
 
 async function getOlmConfig(): Promise<OlmConfig> {
   const olmConfig = await importJSON({ folder: 'secrets', name: 'olm_config' });
   invariant(olmConfig, 'OLM config missing');
   return olmConfig;
 }
 
+export type OLMUtility = {
+  +free: () => void,
+  +sha256: (input: string | Uint8Array) => string,
+  +ed25519_verify: (
+    key: string,
+    message: string | Uint8Array,
+    signature: string,
+  ) => void,
+};
+
 export { getOlmConfig };