diff --git a/nixos/modules/installer/cd-dvd/iso-image.nix b/nixos/modules/installer/cd-dvd/iso-image.nix
index 22f31c460802..84de7800c2a9 100644
--- a/nixos/modules/installer/cd-dvd/iso-image.nix
+++ b/nixos/modules/installer/cd-dvd/iso-image.nix
@@ -176,7 +176,10 @@ in
     # UUID of the USB stick.  It would be nicer to write
     # `root=/dev/disk/by-label/...' here, but UNetbootin doesn't
     # recognise that.
-    boot.kernelParams = [ "root=LABEL=${config.isoImage.volumeID}" ];
+    boot.kernelParams =
+      [ "root=LABEL=${config.isoImage.volumeID}"
+        "boot.shell_on_fail"
+      ];
 
     fileSystems."/" =
       { fsType = "tmpfs";