diff --git a/radvd.spec b/radvd.spec
index 69e7a3a..ddefcc4 100644
--- a/radvd.spec
+++ b/radvd.spec
@@ -9,7 +9,7 @@ Group:     System Environment/Daemons
 Source:    http://www.litech.org/radvd/radvd-%{version}.tar.gz
 PreReq:    chkconfig, /usr/sbin/useradd, /sbin/service, initscripts
 BuildRoot: %{_tmppath}/%{name}-root
-BuildRequires: flex
+BuildRequires: flex, byacc
 
 %description
 radvd is the router advertisement daemon for IPv6.  It listens to router