diff --git a/scripts/nix-build.in b/scripts/nix-build.in
index 4339899fc..ca43041b7 100755
--- a/scripts/nix-build.in
+++ b/scripts/nix-build.in
@@ -278,10 +278,10 @@ foreach my $expr (@exprs) {
             ($pure ? '' : 'p=$PATH; ' ) .
             'dontAddDisableDepTrack=1; ' .
             '[ -e $stdenv/setup ] && source $stdenv/setup; ' .
-            'if [ "$(type -t runHook)" = function ]; then runHook shellHook; fi; ' .
             ($pure ? '' : 'PATH=$PATH:$p; unset p; ') .
             'set +e; ' .
             '[ -n "$PS1" ] && PS1="\n\[\033[1;32m\][nix-shell:\w]$\[\033[0m\] "; ' .
+            'if [ "$(type -t runHook)" = function ]; then runHook shellHook; fi; ' .
             'unset NIX_ENFORCE_PURITY; ' .
             'unset NIX_INDENT_MAKE; ' .
             'shopt -u nullglob; ' .