diff --git a/modules/system/boot/stage-1-init.sh b/modules/system/boot/stage-1-init.sh
index 24c55d47e59b..53df49599f6c 100644
--- a/modules/system/boot/stage-1-init.sh
+++ b/modules/system/boot/stage-1-init.sh
@@ -77,7 +77,7 @@ for o in $(cat /proc/cmdline); do
         debug1mounts) # stop after mounting file systems
             debug1mounts=1
             ;;
-        stage1panic)
+        stage1panic=1)
             panicOnFail=1
             ;;
         root=*)
diff --git a/modules/testing/test-instrumentation.nix b/modules/testing/test-instrumentation.nix
index 991c5d263a5b..d1b3fe154d57 100644
--- a/modules/testing/test-instrumentation.nix
+++ b/modules/testing/test-instrumentation.nix
@@ -84,7 +84,7 @@ in
     # Panic if an error occurs in stage 1 (rather than waiting for
     # user intervention). 
     boot.kernelParams =
-      [ "console=tty1" "console=ttyS0" "panic=1" "stage1panic" ];
+      [ "console=tty1" "console=ttyS0" "panic=1" "stage1panic=1" ];
 
     # `xwininfo' is used by the test driver to query open windows.
     environment.systemPackages = [ pkgs.xorg.xwininfo ];