diff --git a/pkgs/stdenv/generic/setup.sh b/pkgs/stdenv/generic/setup.sh
index 4f78713a549..c3b9033b49a 100644
--- a/pkgs/stdenv/generic/setup.sh
+++ b/pkgs/stdenv/generic/setup.sh
@@ -103,6 +103,7 @@ fi
 
 # Execute the pre-hook.
 export SHELL=@shell@
+export CONFIG_SHELL="$SHELL"
 if [ -z "$shell" ]; then export shell=@shell@; fi
 runHook preHook