diff --git a/UM/Application.py b/UM/Application.py
index f8f337a72..e53b81ba7 100644
--- a/UM/Application.py
+++ b/UM/Application.py
@@ -5,6 +5,7 @@ import argparse
 import os
 import sys
 import threading
+import locale
 
 from UM.Controller import Controller
 from UM.Message import Message #For typing.
@@ -77,7 +78,7 @@ class Application:
         self._main_thread = threading.current_thread()  # type: threading.Thread
 
         self.default_theme = self._app_name  # type: str # Default theme is the application name
-        self._default_language = "en_US"  # type: str
+        self._default_language = locale.getdefaultlocale()[0]  # type: str
 
         self.change_log_url = "https://github.com/Ultimaker/Uranium"  # Where to find a more detailed description of the recent updates.