diff --git a/configure.ac b/configure.ac
index 4d8aaae..914b880 100644
--- a/configure.ac
+++ b/configure.ac
@@ -11,6 +11,9 @@ AC_PROG_CXX
 AC_PROG_MKDIR_P
 AC_PROG_INSTALL
 
+AC_CHECK_PROGS([DOXYGEN], [doxygen], [false])
+AC_CHECK_PROGS([SPHINXBUILD], [sphinx-build], [false])
+
 AC_CANONICAL_BUILD
 AC_CANONICAL_HOST
 
diff --git a/docs/Makefile.am b/docs/Makefile.am
index c79f35a..302a029 100644
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -2,11 +2,8 @@
 
 EXTRA_DIST = Doxyfile conf.py index.rst requirements.txt
 
-# TODO: detect programs by autoconf
 BUILDDIR = build
-DOXYGEN = doxygen
 PAPER =
-SPHINXBUILD = sphinx-build
 SPHINXOPTS =
 
 # Internal variables.
diff --git a/docs/conf.py b/docs/conf.py
index a494df1..ff9687c 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -1,5 +1,12 @@
 import os
 
+def get_version(filename):
+    from re import findall
+    with open(filename) as f:
+        versions = dict(findall(r'AC_INIT\(\[(.*?)\],\s*\[(.*?)\].*\)', f.read()))
+    return versions['fsmlite']
+
+
 # https://github.com/rtfd/readthedocs.org/issues/388
 if os.environ.get('READTHEDOCS', None) == 'True':
   from subprocess import call
@@ -8,8 +15,8 @@
 # TODO: extract from autoconf?
 project = 'fsmlite'
 author = 'Thomas Kemmer'
-version = '0.2'
-release = '0.2.1'
+version = get_version(b'../configure.ac')
+release = version
 copyright = '%s, %s' % ('2015-2018', author)
 
 master_doc = 'index'