diff --git a/src/libsystemd-network/fuzz-lldp-rx.c b/src/libsystemd-network/fuzz-lldp-rx.c
index 844957c069..24146b709d 100644
--- a/src/libsystemd-network/fuzz-lldp-rx.c
+++ b/src/libsystemd-network/fuzz-lldp-rx.c
@@ -9,6 +9,7 @@
 #include "fd-util.h"
 #include "fuzz.h"
 #include "lldp-network.h"
+#include "lldp-rx-internal.h"
 
 static int test_fd[2] = EBADF_PAIR;
 
@@ -22,6 +23,7 @@ int lldp_network_bind_raw_socket(int ifindex) {
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         _cleanup_(sd_event_unrefp) sd_event *e = NULL;
         _cleanup_(sd_lldp_rx_unrefp) sd_lldp_rx *lldp_rx = NULL;
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
 
         if (outside_size_range(size, 0, 2048))
                 return 0;
@@ -37,6 +39,8 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         assert_se(write(test_fd[1], data, size) == (ssize_t) size);
         assert_se(sd_event_run(e, 0) >= 0);
 
+        assert_se(lldp_rx_build_neighbors_json(lldp_rx, &v) >= 0);
+
         assert_se(sd_lldp_rx_stop(lldp_rx) >= 0);
         assert_se(sd_lldp_rx_detach_event(lldp_rx) >= 0);
         test_fd[1] = safe_close(test_fd[1]);
diff --git a/src/libsystemd-network/lldp-neighbor.c b/src/libsystemd-network/lldp-neighbor.c
index 3232680bbd..a4384ac2e1 100644
--- a/src/libsystemd-network/lldp-neighbor.c
+++ b/src/libsystemd-network/lldp-neighbor.c
@@ -776,7 +776,7 @@ int lldp_neighbor_build_json(sd_lldp_neighbor *n, JsonVariant **ret) {
         (void) sd_lldp_neighbor_get_system_name(n, &system_name);
         (void) sd_lldp_neighbor_get_system_description(n, &system_description);
 
-        valid_cc = sd_lldp_neighbor_get_enabled_capabilities(n, &cc);
+        valid_cc = sd_lldp_neighbor_get_enabled_capabilities(n, &cc) >= 0;
 
         return json_build(ret, JSON_BUILD_OBJECT(
                                 JSON_BUILD_PAIR_STRING_NON_EMPTY("ChassisID", chassis_id),
diff --git a/test/test-network/systemd-networkd-tests.py b/test/test-network/systemd-networkd-tests.py
index babfc71e91..52496f8322 100755
--- a/test/test-network/systemd-networkd-tests.py
+++ b/test/test-network/systemd-networkd-tests.py
@@ -5328,7 +5328,7 @@ class NetworkdLLDPTests(unittest.TestCase, Utilities):
 
             output = networkctl('lldp')
             print(output)
-            if re.search(r'veth99 .* veth-peer', output):
+            if re.search(r'veth99 .* veth-peer .* .......a...', output):
                 break
         else:
             self.fail()
@@ -5336,30 +5336,87 @@ class NetworkdLLDPTests(unittest.TestCase, Utilities):
         # With interface name
         output = networkctl('lldp', 'veth99');
         print(output)
-        self.assertRegex(output, r'veth99 .* veth-peer')
+        self.assertRegex(output, r'veth99 .* veth-peer .* .......a...')
 
         # With interface name pattern
         output = networkctl('lldp', 've*9');
         print(output)
-        self.assertRegex(output, r'veth99 .* veth-peer')
+        self.assertRegex(output, r'veth99 .* veth-peer .* .......a...')
 
         # json format
         output = networkctl('--json=short', 'lldp')
         print(output)
         self.assertIn('"InterfaceName":"veth99"', output)
         self.assertIn('"PortID":"veth-peer"', output)
+        self.assertIn('"EnabledCapabilities":128', output)
 
         # json format with interface name
         output = networkctl('--json=short', 'lldp', 'veth99')
         print(output)
         self.assertIn('"InterfaceName":"veth99"', output)
         self.assertIn('"PortID":"veth-peer"', output)
+        self.assertIn('"EnabledCapabilities":128', output)
 
         # json format with interface name pattern
         output = networkctl('--json=short', 'lldp', 've*9')
         print(output)
         self.assertIn('"InterfaceName":"veth99"', output)
         self.assertIn('"PortID":"veth-peer"', output)
+        self.assertIn('"EnabledCapabilities":128', output)
+
+        # LLDP neighbors in status
+        output = networkctl_status('veth99')
+        print(output)
+        self.assertRegex(output, r'Connected To: .* on port veth-peer')
+
+        # enable forwarding, to enable the Router flag
+        with open(os.path.join(network_unit_dir, '23-emit-lldp.network'), mode='a', encoding='utf-8') as f:
+            f.write('[Network]\nIPv4Forwarding=yes\n')
+
+        networkctl_reload()
+        self.wait_online('veth-peer:degraded')
+
+        for trial in range(10):
+            if trial > 0:
+                time.sleep(1)
+
+            output = networkctl('lldp')
+            print(output)
+            if re.search(r'veth99 .* veth-peer .* ....r......', output):
+                break
+        else:
+            self.fail()
+
+        # With interface name
+        output = networkctl('lldp', 'veth99');
+        print(output)
+        self.assertRegex(output, r'veth99 .* veth-peer .* ....r......')
+
+        # With interface name pattern
+        output = networkctl('lldp', 've*9');
+        print(output)
+        self.assertRegex(output, r'veth99 .* veth-peer .* ....r......')
+
+        # json format
+        output = networkctl('--json=short', 'lldp')
+        print(output)
+        self.assertIn('"InterfaceName":"veth99"', output)
+        self.assertIn('"PortID":"veth-peer"', output)
+        self.assertIn('"EnabledCapabilities":16', output)
+
+        # json format with interface name
+        output = networkctl('--json=short', 'lldp', 'veth99')
+        print(output)
+        self.assertIn('"InterfaceName":"veth99"', output)
+        self.assertIn('"PortID":"veth-peer"', output)
+        self.assertIn('"EnabledCapabilities":16', output)
+
+        # json format with interface name pattern
+        output = networkctl('--json=short', 'lldp', 've*9')
+        print(output)
+        self.assertIn('"InterfaceName":"veth99"', output)
+        self.assertIn('"PortID":"veth-peer"', output)
+        self.assertIn('"EnabledCapabilities":16', output)
 
         # LLDP neighbors in status
         output = networkctl_status('veth99')