diff --git a/src/core/service.c b/src/core/service.c
index c6835a4d6c..14763a83b0 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -2588,7 +2588,9 @@ static int service_deserialize_item(Unit *u, const char *key, const char *value,
                         log_unit_debug(u, "Failed to parse main-pid value: %s", value);
                 else {
                         service_set_main_pid(s, pid);
-                        unit_watch_pid(UNIT(s), pid);
+                        r = unit_watch_pid(UNIT(s), pid);
+                        if (r < 0)
+                                log_unit_debug_errno(u, r, "Failed to watch main PID, ignoring: %m");
                 }
         } else if (streq(key, "main-pid-known")) {
                 int b;