diff --git a/pkgs/development/interpreters/erlang/27.nix b/pkgs/development/interpreters/erlang/27.nix
index bf392920d555..91845a1bc28a 100644
--- a/pkgs/development/interpreters/erlang/27.nix
+++ b/pkgs/development/interpreters/erlang/27.nix
@@ -1,6 +1,6 @@
 { mkDerivation }:
 
 mkDerivation {
-  version = "27.0.1";
-  sha256 = "sha256-Lp6J9eq6RXDi0RRjeVO/CIa4h/m7/fwOp/y0u0sTdFQ=";
+  version = "27.1.2";
+  sha256 = "sha256-urHJMPo9XG+sIBuCaWvEhAcykGxlVSdKKem7vCiMjcg=";
 }
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 ]