diff --git a/src/ffmpeg.js b/src/ffmpeg.js
index f75daccb..ac924d35 100644
--- a/src/ffmpeg.js
+++ b/src/ffmpeg.js
@@ -37,9 +37,9 @@ function getFfmpegPath() {
 
 function cut(filePath, format, cutFrom, cutTo) {
   return bluebird.try(() => {
-    const ext = path.extname(filePath) || format;
+    const ext = path.extname(filePath) || `.${format}`;
     const outFileAppend = `${util.formatDuration(cutFrom)}-${util.formatDuration(cutTo)}`;
-    const outFile = `${filePath}-${outFileAppend}.${ext}`;
+    const outFile = `${filePath}-${outFileAppend}${ext}`;
 
     console.log('Cutting from', cutFrom, 'to', cutTo);
 
diff --git a/src/renderer.jsx b/src/renderer.jsx
index f8b31022..ace5d6fb 100644
--- a/src/renderer.jsx
+++ b/src/renderer.jsx
@@ -1,4 +1,3 @@
-const bluebird = require('bluebird');
 const electron = require('electron'); // eslint-disable-line
 const $ = require('jquery');
 const keyboardJs = require('keyboardjs');