diff --git a/tzclock-2.6.1-implicit-declaration.patch b/tzclock-2.6.1-implicit-declaration.patch
new file mode 100644
index 0000000..c0ebd56
--- /dev/null
+++ b/tzclock-2.6.1-implicit-declaration.patch
@@ -0,0 +1,10 @@
+--- tzclock-2.6.1/src/screenSize.c.debug	2007-09-30 02:54:23.000000000 +0900
++++ tzclock-2.6.1/src/screenSize.c	2008-04-11 02:16:05.000000000 +0900
+@@ -27,6 +27,7 @@
+  */
+ #include <stdio.h>
+ #include <gdk/gdk.h>
++#include <gtk/gtkmain.h>
+ 
+ /*----------------------------------------------------------------------------------------------------*
+  *                                                                                                    *
diff --git a/tzclock.spec b/tzclock.spec
index 28dd332..b8af156 100644
--- a/tzclock.spec
+++ b/tzclock.spec
@@ -7,6 +7,7 @@ Group:		Amusements/Graphics
 License:	GPLv2
 URL:		http://www.tzclock.org/
 Source0:	http://www.tzclock.org/releases/%{name}-%{version}.tar.gz
+Patch0:		tzclock-2.6.1-implicit-declaration.patch
 BuildRoot:	%{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
 BuildRequires:	libgnomeui-devel
@@ -22,6 +23,7 @@ plus there are many other nice features for you to discover.
 
 %prep
 %setup -q
+%patch0 -p1 -b .def
 
 %build
 %configure
@@ -67,7 +69,7 @@ desktop-file-install \
 %{_mandir}/man1/*
 
 %changelog
-* Fri Apr 11 2008 Mamoru Tasaka <mtasaka@ioa.s.u-tokyo.ac.jp> - 2.6.1-1
+* Fri Apr 11 2008 Mamoru Tasaka <mtasaka@ioa.s.u-tokyo.ac.jp> - 2.6.1-2
 - 2.6.1
 
 * Sat Feb  9 2008 Mamoru Tasaka <mtasaka@ioa.s.u-tokyo.ac.jp>