diff --git a/src/libsystemd-network/sd-dhcp-lease.c b/src/libsystemd-network/sd-dhcp-lease.c
index 4925fa8f19..4e3be98a33 100644
--- a/src/libsystemd-network/sd-dhcp-lease.c
+++ b/src/libsystemd-network/sd-dhcp-lease.c
@@ -931,7 +931,10 @@ int dhcp_lease_parse_search_domains(const uint8_t *option, size_t len, char ***d
         int r;
 
         assert(domains);
-        assert_return(option && len > 0, -ENODATA);
+        assert(option || len == 0);
+
+        if (len == 0)
+                return -EBADMSG;
 
         while (pos < len) {
                 _cleanup_free_ char *name = NULL;
diff --git a/src/libsystemd-network/test-sd-dhcp-lease.c b/src/libsystemd-network/test-sd-dhcp-lease.c
index 3eea1b0d9b..910b622191 100644
--- a/src/libsystemd-network/test-sd-dhcp-lease.c
+++ b/src/libsystemd-network/test-sd-dhcp-lease.c
@@ -60,8 +60,8 @@ TEST(dhcp_lease_parse_search_domains_no_data) {
         _cleanup_strv_free_ char **domains = NULL;
         static const uint8_t optionbuf[3] = {0, 0, 0};
 
-        assert_se(dhcp_lease_parse_search_domains(NULL, 0, &domains) == -ENODATA);
-        assert_se(dhcp_lease_parse_search_domains(optionbuf, 0, &domains) == -ENODATA);
+        assert_se(dhcp_lease_parse_search_domains(NULL, 0, &domains) == -EBADMSG);
+        assert_se(dhcp_lease_parse_search_domains(optionbuf, 0, &domains) == -EBADMSG);
 }
 
 TEST(dhcp_lease_parse_search_domains_loops) {
diff --git a/src/libsystemd/sd-device/sd-device.c b/src/libsystemd/sd-device/sd-device.c
index 75725a75b3..2fbc619a34 100644
--- a/src/libsystemd/sd-device/sd-device.c
+++ b/src/libsystemd/sd-device/sd-device.c
@@ -422,8 +422,13 @@ _public_ int sd_device_new_from_subsystem_sysname(
         int r;
 
         assert_return(ret, -EINVAL);
-        assert_return(path_is_normalized(subsystem), -EINVAL);
-        assert_return(path_is_normalized(sysname), -EINVAL);
+        assert_return(subsystem, -EINVAL);
+        assert_return(sysname, -EINVAL);
+
+        if (!path_is_normalized(subsystem))
+                return -EINVAL;
+        if (!path_is_normalized(sysname))
+                return -EINVAL;
 
         /* translate sysname back to sysfs filename */
         name = strdupa_safe(sysname);
diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index bc82bf3e8d..57127a861a 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -739,6 +739,10 @@ static int netdev_request_to_create(NetDev *netdev) {
         int r;
 
         assert(netdev);
+        assert(netdev->manager);
+
+        if (netdev->manager->test_mode)
+                return 0;
 
         if (netdev_is_stacked(netdev))
                 return 0;