diff -r 55d8fdd38ca4 -r 60fb6aec157d src/cx/buffer.h
--- a/src/cx/buffer.h	Sat Apr 01 11:51:48 2023 +0200
+++ b/src/cx/buffer.h	Mon Apr 03 19:09:31 2023 +0200
@@ -149,11 +149,12 @@
  * @param space pointer to the memory area, or \c NULL to allocate
  * new memory
  * @param capacity the capacity of the buffer
- * @param allocator the allocator this buffer shall use for automatic memory management
+ * @param allocator the allocator this buffer shall use for automatic
+ * memory management. If \c NULL, the default heap allocator will be used.
  * @param flags buffer features (see cx_buffer_s.flags)
  * @return zero on success, non-zero if a required allocation failed
  */
-__attribute__((__nonnull__(1, 4)))
+__attribute__((__nonnull__(1)))
 int cxBufferInit(
         CxBuffer *buffer,
         void *space,