diff --git a/pkgs/development/python-modules/Babel/default.nix b/pkgs/development/python-modules/Babel/default.nix
index 97b3525782098c..683c94b5ed1ceb 100644
--- a/pkgs/development/python-modules/Babel/default.nix
+++ b/pkgs/development/python-modules/Babel/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, lib, buildPythonPackage, fetchPypi, pytz, pytest, freezegun, glibcLocales }:
+{ stdenv, lib, buildPythonPackage, fetchPypi, pytz, pytest, freezegun, isPy3k, glibcLocales }:
 
 buildPythonPackage rec {
   pname = "Babel";
@@ -11,12 +11,24 @@ buildPythonPackage rec {
 
   propagatedBuildInputs = [ pytz ];
 
-  checkInputs = [ pytest freezegun glibcLocales ];
+  checkInputs = [ pytest freezegun ]
+    # Without this, tests fail with a unicode error on Python < 3
+    # (checked with 2.7) if glibc is used, see:
+    # https://github.com/NixOS/nixpkgs/issues/74904
+    ++ lib.optionals (!isPy3k && stdenv.hostPlatform.libc == "glibc") [ glibcLocales ];
 
-  doCheck = !stdenv.isDarwin;
+  doCheck = !stdenv.isDarwin
+    # Test failure on musl when Python < 3 (checked with 2.7) is used:
+    # https://github.com/NixOS/nixpkgs/issues/74904 (like above).
+    && !(stdenv.hostPlatform.isMusl && !isPy3k);
 
-  preCheck = ''
-    export LC_ALL="en_US.UTF-8"
+  # Without this, the build oddly fails on ofborg CI (but not on nh2's NixOS)
+  # when Python M 3 is used.
+  # Even more oddly, using `export LC_ALL="C.UTF-8"` (with quotes) makes it
+  # fail as well.
+  # See https://github.com/NixOS/nixpkgs/pull/75676#issuecomment-567289105
+  preCheck = if isPy3k then null else ''
+    export LC_ALL=C.UTF-8
   '';
 
   meta = with lib; {