diff --git a/alex.spec b/alex.spec
index 4eabde7..61bb0e5 100644
--- a/alex.spec
+++ b/alex.spec
@@ -1,6 +1,6 @@
 Name:           alex
 Version:        2.1.0
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        The lexer generator for Haskell
 
 Group:          Development/Tools
@@ -9,7 +9,7 @@ URL:            http://haskell.org/alex/
 Source:         http://haskell.org/alex/dist/%{version}/alex-%{version}.tar.gz
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
-BuildRequires:  ghc docbook-style-xsl libxslt
+BuildRequires:  autoconf ghc docbook-style-xsl libxslt
 
 %description
 Alex is a tool for generating lexical analysers in Haskell, given a
@@ -47,6 +47,9 @@ rm -rf ${RPM_BUILD_ROOT}
 
 
 %changelog
+* Tue Sep 25 2007 Bryan O'Sullivan <bos@serpentine.com> - 2.1.0-4
+- build requires autoconf
+
 * Sun Jul 22 2007 Bryan O'Sullivan <bos@serpentine.com> - 2.1.0-3
 - apply a few cleanups from Jens Petersen