diff --git a/libwvstreams.spec b/libwvstreams.spec
index 808fa4e..13b3394 100644
--- a/libwvstreams.spec
+++ b/libwvstreams.spec
@@ -1,6 +1,6 @@
 Name: libwvstreams
 Version: 4.6.1
-Release: 3%{?dist}
+Release: 4%{?dist}
 Summary: WvStreams is a network programming library written in C++
 Source: http://wvstreams.googlecode.com/files/wvstreams-%{version}.tar.gz
 #fixed multilib issue (bug #192717)
@@ -14,6 +14,8 @@ Patch4: wvstreams-4.6.1-statinclude.patch
 #const X509V3_EXT_METHOD * -> X509V3_EXT_METHOD * conversion not allowed
 #by rawhide gcc
 Patch5: wvstreams-4.6.1-gcc.patch
+# fix missing unistd.h header for gcc 4.7
+Patch6: wvstreams-4.6.1-gcc47.patch
 URL: http://alumnit.ca/wiki/index.php?page=WvStreams
 Group: System Environment/Libraries
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@@ -41,6 +43,7 @@ needed for developing applications which use WvStreams.
 %patch3 -p1 -b .make
 %patch4 -p1 -b .statinclude
 %patch5 -p1 -b .gcc
+%patch6 -p1 -b .gcc47
 
 %build
 #  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
@@ -93,6 +96,9 @@ rm -rf $RPM_BUILD_ROOT
 %postun -p /sbin/ldconfig
 
 %changelog
+* Thu Jan 05 2012 Jan Synáček <jsynacek@redhat.com> - 4.6.1-4
+- Fix missing unistd.h header for gcc 4.7
+
 * Tue Feb 08 2011 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 4.6.1-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_15_Mass_Rebuild
 
diff --git a/wvstreams-4.6.1-gcc47.patch b/wvstreams-4.6.1-gcc47.patch
new file mode 100644
index 0000000..3d67048
--- /dev/null
+++ b/wvstreams-4.6.1-gcc47.patch
@@ -0,0 +1,10 @@
+--- wvstreams-4.6.1-dist/include/wvuid.h	2012-01-05 10:18:58.713661236 +0100
++++ wvstreams-4.6.1/include/wvuid.h	2012-01-05 10:27:42.198435328 +0100
+@@ -7,6 +7,7 @@
+ #ifndef __WVUID_H
+ #define __WVUID_H
+ 
++#include <unistd.h>
+ #include "wvstring.h"
+ 
+ #if WIN32