--- a/src/cx/array_list.h	Thu Dec 18 14:53:16 2025 +0100
+++ b/src/cx/array_list.h	Thu Dec 18 16:43:05 2025 +0100
@@ -561,7 +561,7 @@
  * @retval zero success
  * @retval non-zero a re-allocation was necessary but failed
  */
-cx_attr_nonnull
+cx_attr_nonnull_arg(1, 2, 4, 6)
 CX_EXPORT int cx_array_insert_sorted_c_(const CxAllocator *allocator, CxArray *array,
         size_t elem_size, const void *sorted_data, size_t n,
         cx_compare_func2 cmp_func, void *context, bool allow_duplicates);