diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index d36d11f41..117839c51 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,4 +1,8 @@
-2008-04-20  Corinna Vinschen  <corinna@vinschen.de>
+2008-04-21  Corinna Vinschen  <corinna@vinschen.de>
+
+	* kernel32.cc (CreateFileMappingW): Fix bug in reserve/commit handling.
+
+2008-04-21  Corinna Vinschen  <corinna@vinschen.de>
 
 	* Makefile.in (DLL_OFILES): Add kernel32.o.
 	* autoload.cc (WSACloseEvent): Remove.
diff --git a/winsup/cygwin/kernel32.cc b/winsup/cygwin/kernel32.cc
index f8953327d..525432a00 100644
--- a/winsup/cygwin/kernel32.cc
+++ b/winsup/cygwin/kernel32.cc
@@ -331,8 +331,8 @@ CreateFileMappingW (HANDLE hFile, LPSECURITY_ATTRIBUTES lpAttributes,
 			      lpAttributes
 			      ? lpAttributes->lpSecurityDescriptor
 			      : NULL);
-  if (!attribs)
-    attribs = SEC_COMMIT;
+  if (!(attribs & (SEC_RESERVE | SEC_COMMIT)))
+    attribs |= SEC_COMMIT;
   if (hFile == INVALID_HANDLE_VALUE)
     hFile = NULL;
   status = NtCreateSection (&sect, access, &attr, psize, prot, attribs, hFile);