diff --git a/modules/nixos/locales.nix b/modules/nixos/locales.nix
index 5c91d2d..2e81af9 100644
--- a/modules/nixos/locales.nix
+++ b/modules/nixos/locales.nix
@@ -4,18 +4,18 @@
   # set the time zone
   time.timeZone = "Europe/Zurich";
 
-  # set internationalisation properties
+  # keep system language in english, but use swiss locale for formatting
   i18n.defaultLocale = "en_US.UTF-8";
   i18n.extraLocaleSettings = {
-    LC_ADDRESS = "en_US.UTF-8";
-    LC_IDENTIFICATION = "en_US.UTF-8";
-    LC_MEASUREMENT = "en_US.UTF-8";
-    LC_MONETARY = "en_US.UTF-8";
-    LC_NAME = "en_US.UTF-8";
-    LC_NUMERIC = "en_US.UTF-8";
-    LC_PAPER = "en_US.UTF-8";
-    LC_TELEPHONE = "en_US.UTF-8";
-    LC_TIME = "en_US.UTF-8";
+    LC_ADDRESS = "de_CH.UTF-8";
+    LC_IDENTIFICATION = "de_CH.UTF-8";
+    LC_MEASUREMENT = "de_CH.UTF-8";
+    LC_MONETARY = "de_CH.UTF-8";
+    LC_NAME = "de_CH.UTF-8";
+    LC_NUMERIC = "de_CH.UTF-8";
+    LC_PAPER = "de_CH.UTF-8";
+    LC_TELEPHONE = "de_CH.UTF-8";
+    LC_TIME = "de_CH.UTF-8";
   };
 
   # set console font and keymap