diff --git a/headers/os/BeBuild.h b/headers/os/BeBuild.h
index 71736c8e8b..dcfba80924 100644
--- a/headers/os/BeBuild.h
+++ b/headers/os/BeBuild.h
@@ -84,9 +84,11 @@
 	__attribute__((format(__printf__, _format_, _args_)))
 
 #if __GNUC__ >= 4
+# define _ALIGNED_BY_ARG(_no_) __attribute__((alloc_align(_no_)))
 # define _EXPORT __attribute__((visibility("default")))
 # define B_ALWAYS_INLINE __attribute__((always_inline)) inline
 #else
+# define _ALIGNED_BY_ARG(_no_)
 # define _EXPORT
 #endif
 #define _IMPORT
diff --git a/headers/posix/malloc.h b/headers/posix/malloc.h
index 7754038311..5f8d2d804d 100644
--- a/headers/posix/malloc.h
+++ b/headers/posix/malloc.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 Haiku, Inc. All Rights Reserved.
+ * Copyright 2002-2021 Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef _MALLOC_H
@@ -17,7 +17,7 @@ extern void *malloc(size_t numBytes);
 extern void *realloc(void *oldPointer, size_t newSize);
 extern void *calloc(size_t numElements, size_t size);
 extern void free(void *pointer);
-extern void *memalign(size_t alignment, size_t numBytes);
+extern void *memalign(size_t alignment, size_t numBytes) _ALIGNED_BY_ARG(1);
 extern void *valloc(size_t numBytes);
 
 #ifdef _GNU_SOURCE
diff --git a/headers/posix/stdlib.h b/headers/posix/stdlib.h
index ebaa9ec96a..9ab024e472 100644
--- a/headers/posix/stdlib.h
+++ b/headers/posix/stdlib.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 Haiku, Inc. All Rights Reserved.
+ * Copyright 2002-2021 Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef _STDLIB_H_
@@ -50,7 +50,7 @@ extern void		free(void *pointer);
 extern void		*malloc(size_t size);
 extern int		posix_memalign(void **_pointer, size_t alignment, size_t size);
 #ifdef _ISOC11_SOURCE
-extern void 	*aligned_alloc(size_t alignment, size_t size);
+extern void 	*aligned_alloc(size_t alignment, size_t size) _ALIGNED_BY_ARG(1);
 #endif
 extern void		*realloc(void *oldPointer, size_t newSize);
 
diff --git a/headers/private/kernel/heap.h b/headers/private/kernel/heap.h
index 3ac8b8a6e6..7955a8ffa5 100644
--- a/headers/private/kernel/heap.h
+++ b/headers/private/kernel/heap.h
@@ -59,10 +59,10 @@ extern "C" {
 #endif
 
 
-void* memalign_etc(size_t alignment, size_t size, uint32 flags);
+void* memalign_etc(size_t alignment, size_t size, uint32 flags) _ALIGNED_BY_ARG(1);
 void free_etc(void* address, uint32 flags);
 
-void* memalign(size_t alignment, size_t size);
+void* memalign(size_t alignment, size_t size) _ALIGNED_BY_ARG(1);
 
 void deferred_free(void* block);
 
@@ -74,7 +74,7 @@ void heap_add_area(heap_allocator* heap, area_id areaID, addr_t base,
 	size_t size);
 heap_allocator*	heap_create_allocator(const char* name, addr_t base,
 	size_t size, const heap_class* heapClass, bool allocateOnHeap);
-void* heap_memalign(heap_allocator* heap, size_t alignment, size_t size);
+void* heap_memalign(heap_allocator* heap, size_t alignment, size_t size) _ALIGNED_BY_ARG(2);
 status_t heap_free(heap_allocator* heap, void* address);
 
 #if KERNEL_HEAP_LEAK_CHECK