diff --git a/pkgs/applications/networking/instant-messengers/turses/default.nix b/pkgs/applications/networking/instant-messengers/turses/default.nix
index 780dab79e997..27977dae15f8 100644
--- a/pkgs/applications/networking/instant-messengers/turses/default.nix
+++ b/pkgs/applications/networking/instant-messengers/turses/default.nix
@@ -15,6 +15,8 @@ buildPythonPackage rec {
   checkInputs = [ mock pytest coverage tox ];
   propagatedBuildInputs = [ urwid tweepy future ];
 
+  LC_ALL = "en_US.UTF-8";
+
   patches = [
     (fetchpatch {
       url = "https://github.com/louipc/turses/commit/be0961b51f502d49fd9e2e5253ac130e543a31c7.patch";