diff --git a/src/firstboot/firstboot.c b/src/firstboot/firstboot.c
index 652a6d5c89..76af4e4ed5 100644
--- a/src/firstboot/firstboot.c
+++ b/src/firstboot/firstboot.c
@@ -458,6 +458,20 @@ static int process_locale(int rfd) {
         return 1;
 }
 
+static bool keymap_exists_bool(const char *name) {
+        return keymap_exists(name) > 0;
+}
+
+static typeof(&keymap_is_valid) determine_keymap_validity_func(int rfd) {
+        int r;
+
+        r = dir_fd_is_root(rfd);
+        if (r < 0)
+                log_debug_errno(r, "Unable to determine if operating on host root directory, assuming we are: %m");
+
+        return r != 0 ? keymap_exists_bool : keymap_is_valid;
+}
+
 static int prompt_keymap(int rfd) {
         _cleanup_strv_free_ char **kmaps = NULL;
         int r;
@@ -489,7 +503,7 @@ static int prompt_keymap(int rfd) {
         print_welcome(rfd);
 
         return prompt_loop("Please enter system keymap name or number",
-                           kmaps, 60, keymap_is_valid, &arg_keymap);
+                           kmaps, 60, determine_keymap_validity_func(rfd), &arg_keymap);
 }
 
 static int process_keymap(int rfd) {
@@ -1695,6 +1709,8 @@ static int run(int argc, char *argv[]) {
         /* We check these conditions here instead of in parse_argv() so that we can take the root directory
          * into account. */
 
+        if (arg_keymap && !determine_keymap_validity_func(rfd)(arg_keymap))
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Keymap %s is not installed.", arg_keymap);
         if (arg_locale && !locale_is_ok(rfd, arg_locale))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Locale %s is not installed.", arg_locale);
         if (arg_locale_messages && !locale_is_ok(rfd, arg_locale_messages))