Index: uspace/lib/libc/generic/malloc.c
===================================================================
--- uspace/lib/libc/generic/malloc.c	(revision 4b2c458c1ae1c1e7d61cae43c278078e533b58cb)
+++ uspace/lib/libc/generic/malloc.c	(revision f450280b09f45d3bd470438388298f850df05332)
@@ -385,5 +385,5 @@
 	
 	void *ptr = NULL;
-	size_t real_size = GROSS_SIZE(size);
+	size_t real_size = GROSS_SIZE(ALIGN_UP(size, BASE_ALIGN));
 	size_t orig_size = head->size;
 	
@@ -410,5 +410,5 @@
 			block_check(next_head);
 			block_init(head, head->size + next_head->size, false);
-			split_mark(head, size);
+			split_mark(head, ALIGN_UP(size, BASE_ALIGN));
 			
 			ptr = ((void *) head) + sizeof(heap_block_head_t);