diff -r 943bfd9e7978 -r 0ac4aa1737fd tests/test_list.c
--- a/tests/test_list.c	Fri Oct 17 14:14:21 2025 +0200
+++ b/tests/test_list.c	Fri Oct 17 15:04:56 2025 +0200
@@ -1814,6 +1814,67 @@
     }
 })
 
+roll_out_test_combos_with_defaulted_funcs(insert_unique_not_sorted, {
+    int d1 = 50;
+    int d2 = 80;
+    int d3 = 60;
+    int d4 = 40;
+    int d5 = 70;
+    int d6a[6] = array_init(52, 54, 56, 62, 64, 75);
+    int d7a[6] = array_init(51, 57, 58, 65, 77, 78);
+    int d8 = 90;
+    int d9 = 56;
+    int d10a[3] = array_init(67, 75, 90);
+    int *d6ptr[6];
+    int *d7ptr[6];
+    int *d10ptr[3];
+    for (size_t i = 0; i < 6; i++) {
+        d6ptr[i] = &d6a[i];
+        d7ptr[i] = &d7a[i];
+    }
+    for (size_t i = 0 ; i < 3 ; i++) {
+        d10ptr[i] = &d10a[i];
+    }
+    size_t inserted;
+    int expected[19] = array_init(
+        50, 80, 60, 40, 70, 52, 54, 56, 62, 64,
+        75, 51, 57, 58, 65, 77, 78, 90, 67
+    );
+
+    // begin with an unsorted list!
+    CX_TEST_ASSERT(0 == cxListAdd(list, &d1));
+    CX_TEST_ASSERT(0 == cxListAdd(list, &d2));
+    CX_TEST_ASSERT(0 == cxListAdd(list, &d3));
+    CX_TEST_ASSERT(0 == cxListAdd(list, &d4));
+
+    // not start adding unique items
+    CX_TEST_ASSERT(0 == cxListInsertUnique(list, &d5));
+    if (isptrlist) {
+        inserted = cxListInsertUniqueArray(list, d6ptr, 6);
+    } else {
+        inserted = cxListInsertUniqueArray(list, d6a, 6);
+    }
+    CX_TEST_ASSERT(inserted == 6);
+    if (isptrlist) {
+        inserted = cxListInsertUniqueArray(list, d7ptr, 6);
+    } else {
+        inserted = cxListInsertUniqueArray(list, d7a, 6);
+    }
+    CX_TEST_ASSERT(inserted == 6);
+    CX_TEST_ASSERT(0 == cxListInsertUnique(list, &d8));
+    CX_TEST_ASSERT(0 == cxListInsertUnique(list, &d9));
+    if (isptrlist) {
+        inserted = cxListInsertUniqueArray(list, d10ptr, 3);
+    } else {
+        inserted = cxListInsertUniqueArray(list, d10a, 3);
+    }
+    CX_TEST_ASSERT(inserted == 3);
+    CX_TEST_ASSERT(cxListSize(list) == 19);
+    for (size_t i = 0; i < 19; i++) {
+        CX_TEST_ASSERT(*(int *) cxListAt(list, i) == expected[i]);
+    }
+})
+
 roll_out_test_combos(remove, {
     const size_t testdata_len = 32;
     int *testdata = int_test_data_added_to_list(list, isptrlist, testdata_len);
@@ -2554,6 +2615,8 @@
     cx_test_register(suite, test_list_parl_insert_sorted);
     cx_test_register(suite, test_list_arl_insert_unique);
     cx_test_register(suite, test_list_parl_insert_unique);
+    cx_test_register(suite, test_list_arl_insert_unique_not_sorted);
+    cx_test_register(suite, test_list_parl_insert_unique_not_sorted);
     cx_test_register(suite, test_list_arl_remove);
     cx_test_register(suite, test_list_parl_remove);
     cx_test_register(suite, test_list_arl_remove_and_get);
@@ -2611,6 +2674,8 @@
     cx_test_register(suite, test_list_parlm_insert_sorted);
     cx_test_register(suite, test_list_arlm_insert_unique);
     cx_test_register(suite, test_list_parlm_insert_unique);
+    cx_test_register(suite, test_list_arlm_insert_unique_not_sorted);
+    cx_test_register(suite, test_list_parlm_insert_unique_not_sorted);
     cx_test_register(suite, test_list_arlm_swap);
     cx_test_register(suite, test_list_parlm_swap);
     cx_test_register(suite, test_list_arlm_sort);
@@ -2666,6 +2731,8 @@
     cx_test_register(suite, test_list_pll_insert_sorted);
     cx_test_register(suite, test_list_ll_insert_unique);
     cx_test_register(suite, test_list_pll_insert_unique);
+    cx_test_register(suite, test_list_ll_insert_unique_not_sorted);
+    cx_test_register(suite, test_list_pll_insert_unique_not_sorted);
     cx_test_register(suite, test_list_ll_remove);
     cx_test_register(suite, test_list_pll_remove);
     cx_test_register(suite, test_list_ll_remove_and_get);
@@ -2722,6 +2789,8 @@
     cx_test_register(suite, test_list_pllm_insert_sorted);
     cx_test_register(suite, test_list_llm_insert_unique);
     cx_test_register(suite, test_list_pllm_insert_unique);
+    cx_test_register(suite, test_list_llm_insert_unique_not_sorted);
+    cx_test_register(suite, test_list_pllm_insert_unique_not_sorted);
     cx_test_register(suite, test_list_llm_swap);
     cx_test_register(suite, test_list_pllm_swap);
     cx_test_register(suite, test_list_llm_sort);
@@ -2750,6 +2819,8 @@
     cx_test_register(suite, test_list_pkvl_insert_sorted);
     cx_test_register(suite, test_list_kvl_insert_unique);
     cx_test_register(suite, test_list_pkvl_insert_unique);
+    cx_test_register(suite, test_list_kvl_insert_unique_not_sorted);
+    cx_test_register(suite, test_list_pkvl_insert_unique_not_sorted);
     cx_test_register(suite, test_list_kvl_remove);
     cx_test_register(suite, test_list_pkvl_remove);
     cx_test_register(suite, test_list_kvl_remove_and_get);