diff --git a/src/core/nm-l3-config-data.c b/src/core/nm-l3-config-data.c
index 0b2804fa72..13a84d51f0 100644
--- a/src/core/nm-l3-config-data.c
+++ b/src/core/nm-l3-config-data.c
@@ -2604,15 +2604,15 @@ nm_l3_config_data_cmp_full(const NML3ConfigData *a,
         const NMPObject *def_route_a = a->best_default_route_x[IS_IPv4];
         const NMPObject *def_route_b = b->best_default_route_x[IS_IPv4];
 
-        if (def_route_a != def_route_b) {
-            if (NM_FLAGS_HAS(flags, NM_L3_CONFIG_CMP_FLAGS_ROUTES)) {
-                NM_CMP_RETURN(
-                    nmp_object_cmp_full(def_route_a,
-                                        def_route_b,
-                                        NM_FLAGS_HAS(flags, NM_L3_CONFIG_CMP_FLAGS_IFINDEX)
-                                            ? NMP_OBJECT_CMP_FLAGS_NONE
-                                            : NMP_OBJECT_CMP_FLAGS_IGNORE_IFINDEX));
-            } else if (NM_FLAGS_HAS(flags, NM_L3_CONFIG_CMP_FLAGS_ROUTES_ID)) {
+        if (NM_FLAGS_HAS(flags, NM_L3_CONFIG_CMP_FLAGS_ROUTES)) {
+            NM_CMP_RETURN(nmp_object_cmp_full(def_route_a,
+                                              def_route_b,
+                                              NM_FLAGS_HAS(flags, NM_L3_CONFIG_CMP_FLAGS_IFINDEX)
+                                                  ? NMP_OBJECT_CMP_FLAGS_NONE
+                                                  : NMP_OBJECT_CMP_FLAGS_IGNORE_IFINDEX));
+        } else if (NM_FLAGS_HAS(flags, NM_L3_CONFIG_CMP_FLAGS_ROUTES_ID)) {
+            NM_CMP_DIRECT(!!def_route_a, !!def_route_b);
+            if (def_route_a && def_route_b) {
                 if (NM_FLAGS_HAS(flags, NM_L3_CONFIG_CMP_FLAGS_IFINDEX)) {
                     NM_CMP_DIRECT(def_route_a->obj_with_ifindex.ifindex,
                                   def_route_b->obj_with_ifindex.ifindex);
diff --git a/src/core/tests/test-core.c b/src/core/tests/test-core.c
index cb09ac3862..51f4d4ab1c 100644
--- a/src/core/tests/test-core.c
+++ b/src/core/tests/test-core.c
@@ -20,6 +20,7 @@
 #include "dns/nm-dns-manager.h"
 #include "nm-connectivity.h"
 #include "nm-firewall-utils.h"
+#include "nm-l3-config-data.h"
 
 #include "nm-test-utils-core.h"
 
@@ -2823,6 +2824,51 @@ test_icmp6_checksum(void)
 
 /*****************************************************************************/
 
+static void
+test_l3_config_data_cmp_default_routes(void)
+{
+    nm_auto_unref_dedup_multi_index NMDedupMultiIndex *multi_idx = nm_dedup_multi_index_new();
+    nm_auto_unref_l3cd_init NML3ConfigData            *a         = NULL;
+    nm_auto_unref_l3cd_init NML3ConfigData            *b         = NULL;
+    const int                                          IFINDEX   = 1;
+
+    a = nm_l3_config_data_new(multi_idx, IFINDEX, NM_IP_CONFIG_SOURCE_USER);
+    nm_l3_config_data_add_route_4(
+        a,
+        NM_PLATFORM_IP4_ROUTE_INIT(.ifindex = IFINDEX,
+                                   .network = 0,
+                                   .plen    = 0,
+                                   .gateway = nmtst_inet4_from_string("192.168.1.1"),
+                                   .metric  = 100));
+
+    b = nm_l3_config_data_new(multi_idx, IFINDEX, NM_IP_CONFIG_SOURCE_USER);
+    nm_l3_config_data_add_route_4(
+        b,
+        NM_PLATFORM_IP4_ROUTE_INIT(.ifindex       = IFINDEX,
+                                   .network       = 0,
+                                   .plen          = 0,
+                                   .gateway       = nmtst_inet4_from_string("192.168.1.1"),
+                                   .metric        = 100,
+                                   .table_coerced = nm_platform_route_table_coerce(100)));
+
+    nm_l3_config_data_seal(a);
+    nm_l3_config_data_seal(b);
+
+    g_assert(nm_l3_config_data_get_best_default_route(a, AF_INET));
+    g_assert(!nm_l3_config_data_get_best_default_route(b, AF_INET));
+
+    g_assert_cmpint(nm_l3_config_data_cmp_full(a, b, NM_L3_CONFIG_CMP_FLAGS_ROUTES_ID), !=, 0);
+    g_assert_cmpint(nm_l3_config_data_cmp_full(b, a, NM_L3_CONFIG_CMP_FLAGS_ROUTES_ID), !=, 0);
+
+    g_assert_cmpint(nm_l3_config_data_cmp_full(b, a, NM_L3_CONFIG_CMP_FLAGS_ADDRESSES), ==, 0);
+    g_assert_cmpint(nm_l3_config_data_cmp_full(b, a, NM_L3_CONFIG_CMP_FLAGS_ADDRESSES), ==, 0);
+
+    g_assert_cmpint(nm_l3_config_data_cmp_full(a, a, NM_L3_CONFIG_CMP_FLAGS_ALL), ==, 0);
+    g_assert_cmpint(nm_l3_config_data_cmp_full(b, b, NM_L3_CONFIG_CMP_FLAGS_ALL), ==, 0);
+}
+
+/*****************************************************************************/
+
 NMTST_DEFINE();
 
 int
@@ -2901,5 +2947,8 @@ main(int argc, char **argv)
 
     g_test_add_func("/core/general/test_icmp6_checksum", test_icmp6_checksum);
 
+    g_test_add_func("/core/general/test_l3_config_data_cmp_default_routes",
+                    test_l3_config_data_cmp_default_routes);
+
     return g_test_run();
 }