diff --git a/pkgs/development/interpreters/erlang/generic-builder.nix b/pkgs/development/interpreters/erlang/generic-builder.nix
index 38af8a6e0926..2b363d4a06e6 100644
--- a/pkgs/development/interpreters/erlang/generic-builder.nix
+++ b/pkgs/development/interpreters/erlang/generic-builder.nix
@@ -98,6 +98,8 @@ stdenv.mkDerivation ({
 
   inherit src version;
 
+  LANG = "C.UTF-8";
+
   nativeBuildInputs = [ autoconf makeWrapper perl gnum4 libxslt libxml2 ];
 
   buildInputs = [ ncurses opensslPackage ]