diff --git a/src/libnm-core-impl/tests/test-general.c b/src/libnm-core-impl/tests/test-general.c
index 8a98265abb..84d9caaeae 100644
--- a/src/libnm-core-impl/tests/test-general.c
+++ b/src/libnm-core-impl/tests/test-general.c
@@ -1417,6 +1417,7 @@ _do_test_c_list_sort(CListSort *elements, guint n_list, gboolean headless)
 
     g_assert(!c_list_is_empty(&head));
     g_assert(c_list_length(&head) == n_list);
+    g_assert(c_list_is_empty_or_single(&head) == (n_list <= 1));
 
     el_prev = NULL;
     c_list_for_each (iter, &head) {
@@ -1443,6 +1444,10 @@ test_c_list_sort(void)
     guint              n_list;
     guint              repeat;
 
+    g_assert(!c_list_is_linked(NULL));
+    g_assert(c_list_is_empty(NULL));
+    g_assert(c_list_is_empty_or_single(NULL));
+
     {
         CList head;
 
@@ -1450,6 +1455,7 @@ test_c_list_sort(void)
         c_list_sort(&head, _c_list_sort_cmp, NULL);
         g_assert(c_list_length(&head) == 0);
         g_assert(c_list_is_empty(&head));
+        g_assert(c_list_is_empty_or_single(&head));
     }
 
     elements = g_new0(CListSort, N_ELEMENTS);
@@ -1517,6 +1523,8 @@ _do_test_c_list_insert_sorted(CListSort *elements, guint n_list, bool append_equ
     g_assert(c_list_length_is(&head, n_list));
     g_assert(!c_list_length_is(&head, n_list + 1));
 
+    g_assert(c_list_is_empty_or_single(&head) == (n_list <= 1));
+
     el_prev = NULL;
     c_list_for_each_entry (el, &head, lst) {
         if (el_prev) {
diff --git a/src/libnm-std-aux/c-list-util.h b/src/libnm-std-aux/c-list-util.h
index 4800a3cc11..ae2f07ec8c 100644
--- a/src/libnm-std-aux/c-list-util.h
+++ b/src/libnm-std-aux/c-list-util.h
@@ -42,6 +42,12 @@ c_list_length_is(const CList *list, unsigned long check_len)
     return n == check_len;
 }
 
+static inline int
+c_list_is_empty_or_single(const CList *list)
+{
+    return !list || (list->next->next == list);
+}
+
 #define c_list_for_each_prev(_iter, _list) \
     for (_iter = (_list)->prev; (_iter) != (_list); _iter = (_iter)->prev)