diff --git a/bison.spec b/bison.spec
index 1bc29b9..0122099 100644
--- a/bison.spec
+++ b/bison.spec
@@ -23,8 +23,8 @@ Summary:        The GNU Parser Generator
 License:        GPL-3.0-or-later
 Group:          Development/Languages/C and C++
 URL:            http://www.gnu.org/software/bison/bison.html
-Source0:        ftp://ftp.gnu.org/gnu/bison/bison-3.1.tar.xz
-Source1:        ftp://ftp.gnu.org/gnu/bison/bison-3.1.tar.xz.sig
+Source0:        ftp://ftp.gnu.org/gnu/bison/bison-%{version}.tar.xz
+Source1:        ftp://ftp.gnu.org/gnu/bison/bison-%{version}.tar.xz.sig
 Source2:        %{name}.keyring
 Source3:        baselibs.conf
 BuildRequires:  autoconf