diff --git a/pkgs/development/compilers/blackdown/builder.sh b/pkgs/development/compilers/blackdown/builder.sh
index 13aca79e1edf..e44a7d4af942 100755
--- a/pkgs/development/compilers/blackdown/builder.sh
+++ b/pkgs/development/compilers/blackdown/builder.sh
@@ -6,6 +6,11 @@ cp $src .
 bin=`basename $src`
 chmod u+x $bin
 
+# This is required because those GNU coreutils fuckers suddenly
+# removed the `+N' syntax (due to a misguided desire for "standards
+# compliance"), which the Blackdown installer uses.
+export _POSIX2_VERSION=199209
+
 alias more=cat
 yes yes | ./$bin