diff --git a/convert-to-mp3.py b/convert-to-mp3.py
index cabb641..3363b92 100755
--- a/convert-to-mp3.py
+++ b/convert-to-mp3.py
@@ -22,7 +22,7 @@ def main(argv):
 
     for f in args:
         if os.path.isfile(f):
-            Popen(['lame', '-v', '-b', bitrate, f, f + '.mp3']).wait()
+            Popen(['lame', '-v', '-b', str(bitrate), f, f + '.mp3']).wait()
 
 if __name__ == "__main__":
     main(sys.argv)