diff --git a/nixos/modules/installer/tools/nixos-enter.sh b/nixos/modules/installer/tools/nixos-enter.sh
index 6469d9faa03..115b3d7a7c5 100644
--- a/nixos/modules/installer/tools/nixos-enter.sh
+++ b/nixos/modules/installer/tools/nixos-enter.sh
@@ -104,4 +104,6 @@ chroot_add_resolv_conf "$mountPoint" || print "ERROR: failed to set up resolv.co
     chroot "$mountPoint" systemd-tmpfiles --create --remove --exclude-prefix=/dev 1>&2 || true
 )
 
+unset TMPDIR
+
 exec chroot "$mountPoint" "${command[@]}"