diff --git a/main.py b/main.py
old mode 100644
new mode 100755
index 08c040b..0dad531
--- a/main.py
+++ b/main.py
@@ -132,7 +132,7 @@ class App(ttk.Frame):
         initial_dir = os.getcwd()
         if 'HOME' in os.environ:
             initial_dir = os.environ['HOME']
-        self.files = fd.askopenfilename(defaultextension=".mid", filetypes=[("MIDI", ".mid")], initialdir=initial_dir, multiple=True)
+        self.files = fd.askopenfilename(defaultextension=".mid", filetypes=[("MIDI", ".mid"), ("MIDI", ".MID")], initialdir=initial_dir, multiple=True)
         self.midi_file_var.set(self.files)
 
 def main(args):