diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index 4f93ec4c9a..2564295ef0 100644
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -1546,7 +1546,7 @@ static int parse_argv(int argc, char *argv[]) {
                 case 'c':
                         r = safe_atou(optarg, &arg_children_max);
                         if (r < 0)
-                                log_warning("Invalid --children-max ignored: %s", optarg);
+                                log_warning_errno(r, "Failed to parse --children-max= value '%s', ignoring: %m", optarg);
                         break;
                 case 'e':
                         r = parse_sec(optarg, &arg_exec_delay_usec);