diff --git a/ChangeLog b/ChangeLog
index c682aa8..350cf16 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,7 @@ v0.5dev (ongoing development)
  * Fix build if compiled with --enable-permissive-menu-goto (#3599609)
  * glcd driver: Add direct support for framebuffer with paged memory layout
  + hd44780: Added 'raspberrypi' connection type (P. Corner)
+ * Build system: Rename configure.in to configure.ac
 
 v0.5.6
  - Remove deprecated CFontz633 driver. Use CFontzPacket with Model=633 instead!
diff --git a/autogen.sh b/autogen.sh
index c12257a..68ebf79 100644
--- a/autogen.sh
+++ b/autogen.sh
@@ -42,7 +42,7 @@ fi
 
 echo "Running aclocal ..."
 $ACLOCAL
-if grep "^A[CM]_CONFIG_HEADER" configure.in >/dev/null; then
+if grep "^A[CM]_CONFIG_HEADER" configure.ac >/dev/null; then
   echo "Running autoheader..."
   $AUTOHEADER
 fi
diff --git a/configure.in b/configure.ac
similarity index 100%
rename from configure.in
rename to configure.ac
diff --git a/docs/lcdproc-dev/releasing.docbook b/docs/lcdproc-dev/releasing.docbook
index efa26c1..279950e 100644
--- a/docs/lcdproc-dev/releasing.docbook
+++ b/docs/lcdproc-dev/releasing.docbook
@@ -214,7 +214,7 @@ release.
   <title>Files that need version numbers updated</title>
   <listitem><para><filename>BUGS</filename></para></listitem>
   <listitem><para><filename>ChangeLog</filename></para></listitem>
-  <listitem><para><filename>configure.in</filename></para></listitem>
+  <listitem><para><filename>configure.ac</filename></para></listitem>
   <listitem><para><filename>server/menuscreens.c</filename></para></listitem>
   <listitem><para><filename>docs/lcdproc-dev/bookinfo.docbook</filename></para></listitem>
   <listitem><para><filename>docs/lcdproc-dev/driver-api.docbook</filename></para></listitem>
diff --git a/scripts/nightly/make-docs.sh b/scripts/nightly/make-docs.sh
index 9855daa..1cb8830 100755
--- a/scripts/nightly/make-docs.sh
+++ b/scripts/nightly/make-docs.sh
@@ -15,20 +15,21 @@ RSYNC=/usr/bin/rsync
 
 DOCSPATH=${NIGHTLY_DIR}/${BRANCH}/docs/lcdproc-${DOCS}
 DOCSFILE=${DOCSPATH}/lcdproc-${DOCS}.docbook
+CSSFILE=${DOCSPATH}/lcdproc-${DOCS}.css
 
 #############################
 test -d ${NIGHTLY_DIR} && cd ${NIGHTLY_DIR}
 
 # Generate HTML
-${XMLTO}  xhtml-nochunks ${DOCSFILE} >/dev/null  2>&1
+${XMLTO} xhtml-nochunks --stringparam html.stylesheet=${CSSFILE} ${DOCSFILE} >/dev/null 2>&1
 mv lcdproc-${DOCS}.html ${BRANCH}-${DOCS}.html
 
 # Generate PDF
-#${XMLTO} pdf ${DOCSFILE} >/dev/null  2>&1
+#${XMLTO} pdf ${DOCSFILE} >/dev/null 2>&1
 #mv lcdproc-${DOCS}.pdf ${BRANCH}-${DOCS}.pdf
 
 # Generate TXT
-${XMLTO} txt ${DOCSFILE} >/dev/null  2>&1
+${XMLTO} txt ${DOCSFILE} >/dev/null 2>&1
 mv lcdproc-${DOCS}.txt ${BRANCH}-${DOCS}.txt
 
 # Upload to sf.net
diff --git a/scripts/nightly/make-nightly.sh b/scripts/nightly/make-nightly.sh
index b3f1e93..4398903 100755
--- a/scripts/nightly/make-nightly.sh
+++ b/scripts/nightly/make-nightly.sh
@@ -56,14 +56,14 @@ if [ -e README ] && [ -e ChangeLog ] && [ -e LCDd.conf ]; then
   ${CVS2CL} -l '-d yesterday<=' --stdout 2>/dev/null >> ChangeLog
 
   # Change the version number to CVS-${BRANCH}-${DATE}
-  cp -a configure.in configure.in.nightly-temp
+  cp -a configure.ac configure.ac.nightly-temp
   BRANCH=${BRANCH} \
   ${PERL} -MPOSIX -i -p \
           -e '$version = "CVS-".$ENV{BRANCH}."-".strftime("%Y%m%d", localtime);
               s/(AM_INIT_AUTOMAKE\s*)\(\s*(\[?lcdproc\]?)\s*,\s*[\w\d.-]+\s*\)/$1($2, $version)/;
               s/(AC_INIT\s*)\(\s*(\[?lcdproc\]?)\s*,\s*[\w\d.-]+\s*\)/$1($2, $version)/;
               s/(AC_INIT\s*)\(\s*(\[?lcdproc\]?)\s*,\s*[\w\d.-]+(\s*[^)]+)\s*\)/$1($2, $version$3)/;' \
-          configure.in
+          configure.ac
 
   # Debian-specific stuff
   for dir in debian scripts/debian ; do
@@ -102,7 +102,7 @@ if [ -e README ] && [ -e ChangeLog ] && [ -e LCDd.conf ]; then
   rm lcdproc-CVS-${BRANCH}.tar.bz2
 
   # Cleanup
-  mv configure.in.nightly-temp configure.in
+  mv configure.ac.nightly-temp configure.ac
   mv README.nightly-temp README
   mv ChangeLog.nightly-temp ChangeLog
   rm -f nightly-cvsChanges.txt last-nightly.txt
@@ -117,7 +117,7 @@ if [ -e README ] && [ -e ChangeLog ] && [ -e LCDd.conf ]; then
   # re-create files accidentially deleted
   ${CVS} update -d &> /dev/null
 
-  # build configure (& Makefile.in's ?) based on original configure.in from CVS
+  # build configure (& Makefile.in's ?) based on original configure.ac from CVS
   sh autogen.sh >/dev/null
 
 fi