diff --git a/src/cli/index.js b/src/cli/index.js
index a4b307d57a..d0c58f1c6b 100644
--- a/src/cli/index.js
+++ b/src/cli/index.js
@@ -291,7 +291,7 @@ export async function main({
   const runEventuallyWithFile = (mutexFilename: ?string, isFirstTime?: boolean): Promise<void> => {
     return new Promise(resolve => {
       const lockFilename = mutexFilename || path.join(config.cwd, constants.SINGLE_INSTANCE_FILENAME);
-      lockfile.lock(lockFilename, {realpath: false}, (err: mixed, release: () => void) => {
+      lockfile.lock(lockFilename, {realpath: false}, (err: mixed, release: (() => void) => void) => {
         if (err) {
           if (isFirstTime) {
             reporter.warn(reporter.lang('waitingInstance'));
@@ -303,7 +303,7 @@ export async function main({
           onDeath(() => {
             process.exitCode = 1;
           });
-          resolve(run().then(release));
+          resolve(run().then(() => new Promise(resolve => release(resolve))));
         }
       });
     });