diff --git a/payloads/libpayload/libc/malloc.c b/payloads/libpayload/libc/malloc.c
index c03cc737fa..851ef574e2 100644
--- a/payloads/libpayload/libc/malloc.c
+++ b/payloads/libpayload/libc/malloc.c
@@ -37,9 +37,6 @@
  * We're also susceptible to the usual buffer overrun poisoning, though the
  * risk is within acceptable ranges for this implementation (don't overrun
  * your buffers, kids!).
- *
- * The header format (hdrtype_t) supports heaps of up to 32MiB (given that int
- * is 32 bits long).
  */
 
 #define IN_MALLOC_C
@@ -50,7 +47,7 @@ extern char _heap, _eheap;	/* Defined in the ldscript. */
 static void *hstart = (void *)&_heap;
 static void *hend = (void *)&_eheap;
 
-typedef unsigned int hdrtype_t;
+typedef u64 hdrtype_t;
 #define HDRSIZE (sizeof(hdrtype_t))
 
 #define SIZE_BITS ((HDRSIZE << 3) - 7)