diff --git a/index.js b/index.js
index df1ff4d..540790f 100644
--- a/index.js
+++ b/index.js
@@ -2,12 +2,12 @@
 
 const fs = require('fs');
 
-const defOpts = {
-  encoding: 'utf8',
-  lineEnding: '\n'
-};
-
-module.exports = (path, opts = defOpts) => {
+module.exports = (path, usrOpts) => {
+  const opts = {
+    encoding: 'utf8',
+    lineEnding: '\n'
+  };
+  Object.assign(opts, usrOpts);
   return new Promise((resolve, reject) => {
     const rs = fs.createReadStream(path, {encoding: opts.encoding});
     let acc = '';
diff --git a/test/test.js b/test/test.js
index abb57ea..b5ecd5b 100644
--- a/test/test.js
+++ b/test/test.js
@@ -50,6 +50,12 @@ describe('firstline', () => {
         .then(() => firstline(filePath).should.eventually.equal(''))
     );
 
+    it(
+      'should work with a different encoding when specified correctly',
+      () => promisify(fs.writeFile, [filePath, 'abc\ndef\nghi', { encoding: 'ascii' }])
+        .then(() => firstline(filePath, { encoding: 'ascii' }).should.eventually.equal('abc'))
+    );
+
     it(
       'should work with a different line ending when specified correctly',
       () => promisify(fs.writeFile, [filePath, 'abc\rdef\rghi'])