diff --git a/src/switchroot/ostree-mount-util.h b/src/switchroot/ostree-mount-util.h
index eb79efdfbf..608528f35a 100644
--- a/src/switchroot/ostree-mount-util.h
+++ b/src/switchroot/ostree-mount-util.h
@@ -36,6 +36,10 @@
 #define _OSTREE_SYSROOT_READONLY_STAMP "/run/ostree-sysroot-ro.stamp"
 #define _OSTREE_COMPOSEFS_ROOT_STAMP "/run/ostree-composefs-root.stamp"
 
+#define OTCORE_SYSROOT_NOT_WRITEABLE \
+  "sysroot.readonly=true requires %s to be writable at this point, the cmdline should contain rw " \
+  "but not ro, if that is not the case this is likely the issue"
+
 #define autofree __attribute__ ((cleanup (cleanup_free)))
 
 static inline int
diff --git a/src/switchroot/ostree-prepare-root-static.c b/src/switchroot/ostree-prepare-root-static.c
index 4aaa469246..ce3340f83d 100644
--- a/src/switchroot/ostree-prepare-root-static.c
+++ b/src/switchroot/ostree-prepare-root-static.c
@@ -229,8 +229,7 @@ main (int argc, char *argv[])
   if (sysroot_readonly)
     {
       if (!sysroot_currently_writable)
-        errx (EXIT_FAILURE, "sysroot.readonly=true requires %s to be writable at this point",
-              root_arg);
+        errx (EXIT_FAILURE, OTCORE_SYSROOT_NOT_WRITEABLE, root_arg);
       /* Pass on the fact that we discovered a readonly sysroot to ostree-remount.service */
       int fd = open (_OSTREE_SYSROOT_READONLY_STAMP, O_WRONLY | O_CREAT | O_CLOEXEC, 0644);
       if (fd < 0)
diff --git a/src/switchroot/ostree-prepare-root.c b/src/switchroot/ostree-prepare-root.c
index 8d0ab88e44..1a0539e190 100644
--- a/src/switchroot/ostree-prepare-root.c
+++ b/src/switchroot/ostree-prepare-root.c
@@ -557,8 +557,7 @@ main (int argc, char *argv[])
   if (sysroot_readonly)
     {
       if (!sysroot_currently_writable)
-        errx (EXIT_FAILURE, "sysroot.readonly=true requires %s to be writable at this point",
-              root_arg);
+        errx (EXIT_FAILURE, OTCORE_SYSROOT_NOT_WRITEABLE, root_arg);
     }
   /* Pass on the state for use by ostree-prepare-root */
   g_variant_builder_add (&metadata_builder, "{sv}", OTCORE_RUN_BOOTED_KEY_SYSROOT_RO,