diff --git a/pkgs/development/libraries/glibc-2.12/locales.nix b/pkgs/development/libraries/glibc-2.12/locales.nix
index 38f3f0723848..d598e0e094dc 100644
--- a/pkgs/development/libraries/glibc-2.12/locales.nix
+++ b/pkgs/development/libraries/glibc-2.12/locales.nix
@@ -28,12 +28,13 @@ in
         mkdir -p $TMPDIR/"$(dirname $(readlink -f $(type -p localedef)))/../lib/locale"
 
         # Hack to allow building of the locales (needed since glibc-2.12)
-        sed -i -e 's/^LOCALEDEF=/LOCALEDEF?=/' ../glibc-2*/localedata/Makefile
+        sed -i -e "s,^LOCALEDEF=.*,LOCALEDEF=localedef --prefix=$TMPDIR," -e \
+            /library-path/d ../glibc-2*/localedata/Makefile
+        ${if allLocales then "" else
+            "echo SUPPORTED-LOCALES=\"${toString locales}\" > ../glibc-2*/localedata/SUPPORTED"}
 
         make localedata/install-locales \
-            LOCALEDEF="localedef --prefix=$TMPDIR" \
             localedir=$out/lib/locale \
-            ${if allLocales then "" else "SUPPORTED-LOCALES=\"${toString locales}\""}
       '';
 
     installPhase =