diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 8a43e89a8..bbe8e4f62 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,8 @@
+2007-01-12  Corinna Vinschen  <corinna@vinschen.de>
+
+	* cygheap.cc (_csbrk): Fix off-by-one error.
+	* cygwin.sc: Give .cygheap a minimum size of 512K.
+
 2007-01-12  Christopher Faylor  <me@cgf.cx>
 
 	* external.cc (sync_winenv): Use cur_environ () rather than
diff --git a/winsup/cygwin/cygheap.cc b/winsup/cygwin/cygheap.cc
index 9b98b346a..caeda7b3a 100644
--- a/winsup/cygwin/cygheap.cc
+++ b/winsup/cygwin/cygheap.cc
@@ -1,6 +1,6 @@
 /* cygheap.cc: Cygwin heap manager.
 
-   Copyright 2000, 2001, 2002, 2003, 2004, 2005 Red Hat, Inc.
+   Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Red Hat, Inc.
 
    This file is part of Cygwin.
 
@@ -121,7 +121,7 @@ _csbrk (int sbs)
   size_t granmask = getpagesize () - 1;
   char *newbase = nextpage (prebrk);
   cygheap_max = (char *) cygheap_max + sbs;
-  if (!sbs || (newbase > cygheap_max) || (cygheap_max < _cygheap_end))
+  if (!sbs || (newbase >= cygheap_max) || (cygheap_max <= _cygheap_end))
     /* nothing to do */;
   else
     {
diff --git a/winsup/cygwin/cygwin.sc b/winsup/cygwin/cygwin.sc
index 58ee37664..6247e86cc 100644
--- a/winsup/cygwin/cygwin.sc
+++ b/winsup/cygwin/cygwin.sc
@@ -106,7 +106,7 @@ SECTIONS
   {
     __cygheap_mid = .;
     *(.cygheap)
-    . = . + 1;
+    . = . + (512 * 1024);
     . = ALIGN(512 * 1024);
   }
   __cygheap_end = ABSOLUTE(.);