diff --git a/src/core/unit.h b/src/core/unit.h
index 128122b8df..88d1074aac 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -919,7 +919,7 @@ int unit_thaw_vtable_common(Unit *u);
 
 /* Macros which append UNIT= or USER_UNIT= to the message */
 
-#define log_unit_full_errno(unit, level, error, ...)                    \
+#define log_unit_full_errno_zerook(unit, level, error, ...)             \
         ({                                                              \
                 const Unit *_u = (unit);                                \
                 (log_get_max_level() < LOG_PRI(level)) ? -ERRNO_VALUE(error) : \
@@ -927,9 +927,16 @@ int unit_thaw_vtable_common(Unit *u);
                                 log_internal(level, error, PROJECT_FILE, __LINE__, __func__, ##__VA_ARGS__); \
         })
 
-#define log_unit_full(unit, level, ...) (void) log_unit_full_errno(unit, level, 0, __VA_ARGS__)
+#define log_unit_full_errno(unit, level, error, ...) \
+        ({                                                              \
+                int _error = (error);                                   \
+                ASSERT_NON_ZERO(_error);                                \
+                log_unit_full_errno_zerook(unit, level, _error, ##__VA_ARGS__); \
+        })
 
-#define log_unit_debug(unit, ...)   log_unit_full_errno(unit, LOG_DEBUG, 0, __VA_ARGS__)
+#define log_unit_full(unit, level, ...) (void) log_unit_full_errno_zerook(unit, level, 0, __VA_ARGS__)
+
+#define log_unit_debug(unit, ...)   log_unit_full(unit, LOG_DEBUG, __VA_ARGS__)
 #define log_unit_info(unit, ...)    log_unit_full(unit, LOG_INFO, __VA_ARGS__)
 #define log_unit_notice(unit, ...)  log_unit_full(unit, LOG_NOTICE, __VA_ARGS__)
 #define log_unit_warning(unit, ...) log_unit_full(unit, LOG_WARNING, __VA_ARGS__)
diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index b31f0fa81a..81d9260c12 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -747,8 +747,7 @@ int netdev_load_one(Manager *manager, const char *filename) {
                 r = netdev_get_mac(netdev->ifname, &netdev->mac);
                 if (r < 0)
                         return log_netdev_error_errno(netdev, r,
-                                                      "Failed to generate predictable MAC address for %s: %m",
-                                                      netdev->ifname);
+                                                      "Failed to generate predictable MAC address: %m");
         }
 
         r = hashmap_ensure_put(&netdev->manager->netdevs, &string_hash_ops, netdev->ifname, netdev);
@@ -760,8 +759,8 @@ int netdev_load_one(Manager *manager, const char *filename) {
                 assert(n);
                 if (!streq(netdev->filename, n->filename))
                         log_netdev_warning_errno(netdev, r,
-                                                 "The setting Name=%s in %s conflicts with the one in %s, ignoring",
-                                                 netdev->ifname, netdev->filename, n->filename);
+                                                 "Device was already configured by file %s, ignoring %s.",
+                                                 n->filename, netdev->filename);
 
                 /* Clear ifname before netdev_free() is called. Otherwise, the NetDev object 'n' is
                  * removed from the hashmap 'manager->netdevs'. */
diff --git a/src/network/netdev/netdev.h b/src/network/netdev/netdev.h
index 6d149da2e9..08070abd0a 100644
--- a/src/network/netdev/netdev.h
+++ b/src/network/netdev/netdev.h
@@ -5,6 +5,7 @@
 
 #include "conf-parser.h"
 #include "list.h"
+#include "log-link.h"
 #include "networkd-link.h"
 #include "time-util.h"
 
@@ -223,24 +224,32 @@ const struct ConfigPerfItem* network_netdev_gperf_lookup(const char *key, GPERF_
 
 /* Macros which append INTERFACE= to the message */
 
-#define log_netdev_full(netdev, level, error, ...)                      \
+#define log_netdev_full_errno_zerook(netdev, level, error, ...)         \
         ({                                                              \
                 const NetDev *_n = (netdev);                            \
-                _n ? log_object_internal(level, error, PROJECT_FILE, __LINE__, __func__, "INTERFACE=", _n->ifname, NULL, NULL, ##__VA_ARGS__) : \
-                        log_internal(level, error, PROJECT_FILE, __LINE__, __func__, ##__VA_ARGS__); \
+                log_interface_full_errno_zerook(_n ? _n->ifname : NULL, level, error, __VA_ARGS__); \
         })
 
-#define log_netdev_debug(netdev, ...)       log_netdev_full(netdev, LOG_DEBUG, 0, ##__VA_ARGS__)
-#define log_netdev_info(netdev, ...)        log_netdev_full(netdev, LOG_INFO, 0, ##__VA_ARGS__)
-#define log_netdev_notice(netdev, ...)      log_netdev_full(netdev, LOG_NOTICE, 0, ##__VA_ARGS__)
-#define log_netdev_warning(netdev, ...)     log_netdev_full(netdev, LOG_WARNING, 0, ## __VA_ARGS__)
-#define log_netdev_error(netdev, ...)       log_netdev_full(netdev, LOG_ERR, 0, ##__VA_ARGS__)
+#define log_netdev_full_errno(netdev, level, error, ...) \
+        ({                                                              \
+                int _error = (error);                                   \
+                ASSERT_NON_ZERO(_error);                                \
+                log_netdev_full_errno_zerook(netdev, level, _error, __VA_ARGS__); \
+        })
 
-#define log_netdev_debug_errno(netdev, error, ...)   log_netdev_full(netdev, LOG_DEBUG, error, ##__VA_ARGS__)
-#define log_netdev_info_errno(netdev, error, ...)    log_netdev_full(netdev, LOG_INFO, error, ##__VA_ARGS__)
-#define log_netdev_notice_errno(netdev, error, ...)  log_netdev_full(netdev, LOG_NOTICE, error, ##__VA_ARGS__)
-#define log_netdev_warning_errno(netdev, error, ...) log_netdev_full(netdev, LOG_WARNING, error, ##__VA_ARGS__)
-#define log_netdev_error_errno(netdev, error, ...)   log_netdev_full(netdev, LOG_ERR, error, ##__VA_ARGS__)
+#define log_netdev_full(netdev, level, ...) (void) log_netdev_full_errno_zerook(netdev, level, 0, __VA_ARGS__)
+
+#define log_netdev_debug(netdev, ...)   log_netdev_full(netdev, LOG_DEBUG, __VA_ARGS__)
+#define log_netdev_info(netdev, ...)    log_netdev_full(netdev, LOG_INFO, __VA_ARGS__)
+#define log_netdev_notice(netdev, ...)  log_netdev_full(netdev, LOG_NOTICE, __VA_ARGS__)
+#define log_netdev_warning(netdev, ...) log_netdev_full(netdev, LOG_WARNING,  __VA_ARGS__)
+#define log_netdev_error(netdev, ...)   log_netdev_full(netdev, LOG_ERR, __VA_ARGS__)
+
+#define log_netdev_debug_errno(netdev, error, ...)   log_netdev_full_errno(netdev, LOG_DEBUG, error, __VA_ARGS__)
+#define log_netdev_info_errno(netdev, error, ...)    log_netdev_full_errno(netdev, LOG_INFO, error, __VA_ARGS__)
+#define log_netdev_notice_errno(netdev, error, ...)  log_netdev_full_errno(netdev, LOG_NOTICE, error, __VA_ARGS__)
+#define log_netdev_warning_errno(netdev, error, ...) log_netdev_full_errno(netdev, LOG_WARNING, error, __VA_ARGS__)
+#define log_netdev_error_errno(netdev, error, ...)   log_netdev_full_errno(netdev, LOG_ERR, error, __VA_ARGS__)
 
 #define LOG_NETDEV_MESSAGE(netdev, fmt, ...) "MESSAGE=%s: " fmt, (netdev)->ifname, ##__VA_ARGS__
 #define LOG_NETDEV_INTERFACE(netdev) "INTERFACE=%s", (netdev)->ifname
diff --git a/src/network/netdev/wireguard.c b/src/network/netdev/wireguard.c
index 75d6d376a5..b8fc492d4f 100644
--- a/src/network/netdev/wireguard.c
+++ b/src/network/netdev/wireguard.c
@@ -914,14 +914,13 @@ static int wireguard_verify(NetDev *netdev, const char *filename) {
         r = wireguard_read_key_file(w->private_key_file, w->private_key);
         if (r < 0)
                 return log_netdev_error_errno(netdev, r,
-                                              "Failed to read private key from %s. Dropping network device %s.",
-                                              w->private_key_file, netdev->ifname);
+                                              "Failed to read private key from %s. Ignoring network device.",
+                                              w->private_key_file);
 
         if (eqzero(w->private_key))
                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
                                               "%s: Missing PrivateKey= or PrivateKeyFile=, "
-                                              "Dropping network device %s.",
-                                              filename, netdev->ifname);
+                                              "Ignoring network device.", filename);
 
         LIST_FOREACH_SAFE(peers, peer, peer_next, w->peers)
                 if (wireguard_peer_verify(peer) < 0)
diff --git a/src/timedate/timedated.c b/src/timedate/timedated.c
index 452c38e0de..6e0f91dec4 100644
--- a/src/timedate/timedated.c
+++ b/src/timedate/timedated.c
@@ -65,24 +65,33 @@ typedef struct Context {
         LIST_HEAD(UnitStatusInfo, units);
 } Context;
 
-#define log_unit_full(unit, level, error, ...)                          \
+#define log_unit_full_errno_zerook(unit, level, error, ...)             \
         ({                                                              \
                 const UnitStatusInfo *_u = (unit);                      \
-                log_object_internal(level, error, PROJECT_FILE, __LINE__, __func__, \
-                                    "UNIT=", _u->name, NULL, NULL, ##__VA_ARGS__); \
+                _u ? log_object_internal(level, error, PROJECT_FILE, __LINE__, __func__, "UNIT=", _u->name, NULL, NULL, ##__VA_ARGS__) : \
+                        log_internal(level, error, PROJECT_FILE, __LINE__, __func__, ##__VA_ARGS__); \
         })
 
-#define log_unit_debug(unit, ...)   log_unit_full(unit, LOG_DEBUG, 0, ##__VA_ARGS__)
-#define log_unit_info(unit, ...)    log_unit_full(unit, LOG_INFO, 0, ##__VA_ARGS__)
-#define log_unit_notice(unit, ...)  log_unit_full(unit, LOG_NOTICE, 0, ##__VA_ARGS__)
-#define log_unit_warning(unit, ...) log_unit_full(unit, LOG_WARNING, 0, ##__VA_ARGS__)
-#define log_unit_error(unit, ...)   log_unit_full(unit, LOG_ERR, 0, ##__VA_ARGS__)
+#define log_unit_full_errno(unit, level, error, ...) \
+        ({                                                              \
+                int _error = (error);                                   \
+                ASSERT_NON_ZERO(_error);                                \
+                log_unit_full_errno_zerook(unit, level, _error, ##__VA_ARGS__); \
+        })
 
-#define log_unit_debug_errno(unit, error, ...)   log_unit_full(unit, LOG_DEBUG, error, ##__VA_ARGS__)
-#define log_unit_info_errno(unit, error, ...)    log_unit_full(unit, LOG_INFO, error, ##__VA_ARGS__)
-#define log_unit_notice_errno(unit, error, ...)  log_unit_full(unit, LOG_NOTICE, error, ##__VA_ARGS__)
-#define log_unit_warning_errno(unit, error, ...) log_unit_full(unit, LOG_WARNING, error, ##__VA_ARGS__)
-#define log_unit_error_errno(unit, error, ...)   log_unit_full(unit, LOG_ERR, error, ##__VA_ARGS__)
+#define log_unit_full(unit, level, ...) (void) log_unit_full_errno_zerook(unit, level, 0, ##__VA_ARGS__)
+
+#define log_unit_debug(unit, ...)   log_unit_full(unit, LOG_DEBUG, ##__VA_ARGS__)
+#define log_unit_info(unit, ...)    log_unit_full(unit, LOG_INFO, ##__VA_ARGS__)
+#define log_unit_notice(unit, ...)  log_unit_full(unit, LOG_NOTICE, ##__VA_ARGS__)
+#define log_unit_warning(unit, ...) log_unit_full(unit, LOG_WARNING, ##__VA_ARGS__)
+#define log_unit_error(unit, ...)   log_unit_full(unit, LOG_ERR, ##__VA_ARGS__)
+
+#define log_unit_debug_errno(unit, error, ...)   log_unit_full_errno(unit, LOG_DEBUG, error, ##__VA_ARGS__)
+#define log_unit_info_errno(unit, error, ...)    log_unit_full_errno(unit, LOG_INFO, error, ##__VA_ARGS__)
+#define log_unit_notice_errno(unit, error, ...)  log_unit_full_errno(unit, LOG_NOTICE, error, ##__VA_ARGS__)
+#define log_unit_warning_errno(unit, error, ...) log_unit_full_errno(unit, LOG_WARNING, error, ##__VA_ARGS__)
+#define log_unit_error_errno(unit, error, ...)   log_unit_full_errno(unit, LOG_ERR, error, ##__VA_ARGS__)
 
 static void unit_status_info_clear(UnitStatusInfo *p) {
         assert(p);
@@ -485,8 +494,8 @@ static int unit_start_or_stop(UnitStatusInfo *u, sd_bus *bus, sd_bus_error *erro
                 "ss",
                 u->name,
                 "replace");
-        log_unit_full(u, r < 0 ? LOG_WARNING : LOG_DEBUG, r,
-                      "%s unit: %m", start ? "Starting" : "Stopping");
+        log_unit_full_errno_zerook(u, r < 0 ? LOG_WARNING : LOG_DEBUG, r,
+                                   "%s unit: %m", start ? "Starting" : "Stopping");
         if (r < 0)
                 return r;