diff --git a/winsup/mingw/ChangeLog b/winsup/mingw/ChangeLog
index 7d3eb7c62..ed4487b1d 100644
--- a/winsup/mingw/ChangeLog
+++ b/winsup/mingw/ChangeLog
@@ -1,3 +1,12 @@
+2002-01-28  Danny Smith  <dannysmith@users.sourceforge.net>
+
+	* include/malloc.h (_heapinfo): Correct structure definition.
+	(_USEDENTRY,_FREEENTRY): Add defines.
+	Add comment on platform support for _heap* functions.
+	(_get_sbh_threshold): Add prototype.
+	(_set_sbh_threshold): Likewise.
+	(_expand): Likewise.
+
 2002-01-25  Danny Smith  <dannysmith@users.sourceforge.net>
 
 	* profile/profil.c: Update copyright info.
diff --git a/winsup/mingw/include/malloc.h b/winsup/mingw/include/malloc.h
index 85ad4e8d3..9c412404b 100644
--- a/winsup/mingw/include/malloc.h
+++ b/winsup/mingw/include/malloc.h
@@ -41,20 +41,25 @@
 
 /*
  * The structure used to walk through the heap with _heapwalk.
- * TODO: This is a guess at the internals of this structure.
  */
 typedef	struct _heapinfo
 {
-	void*		ptr;
-	unsigned int	size;
-	int		in_use;
+	int*	_pentry;
+	size_t	_size;
+	int	_useflag;
 } _HEAPINFO;
 
+/* Values for _heapinfo.useflag */
+#define _USEDENTRY 0
+#define _FREEENTRY 1
 
 #ifdef	__cplusplus
 extern "C" {
 #endif
-
+/*
+   The _heap* memory allocation functions are supported on NT
+   but not W9x. On latter, they always set errno to ENOSYS.
+*/
 int	_heapwalk (_HEAPINFO*);
 
 #ifndef	_NO_OLDNAMES
@@ -64,7 +69,11 @@ int	heapwalk (_HEAPINFO*);
 int	_heapchk (void);	/* Verify heap integrety. */
 int	_heapmin (void);	/* Return unused heap to the OS. */
 int	_heapset (unsigned int);
+
 size_t	_msize (void*);
+size_t	_get_sbh_threshold (void); 
+int	_set_sbh_threshold (size_t);
+void *	_expand (void*, size_t); 
 
 #ifdef __cplusplus
 }