diff --git a/configure.ac b/configure.ac
index c5f2353..892b0ba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,14 +1,42 @@
+#                                               -*- Autoconf -*-
+# Process this file with autoconf to produce a configure script.
+
+AC_PREREQ([2.69])
 AC_INIT([sermon], [0.9], [david.a.baer@gmail.com])
 AM_INIT_AUTOMAKE([-Wall -Werror foreign])
+AC_CONFIG_SRCDIR([config.h.in])
+AC_CONFIG_HEADERS([config.h])
+
+# Checks for programs.
 AC_PROG_CC
 AC_PROG_LEX
 AC_PROG_YACC
+
+# Checks for libraries.
 PKG_CHECK_MODULES([libxml2], [libxml-2.0])
 PKG_CHECK_MODULES([libxslt], [libxslt])
-AC_CONFIG_HEADERS([config.h])
-AC_CONFIG_FILES([
-  Makefile
-  src/Makefile
-  data/Makefile
-])
+AC_CHECK_LIB([bsd], [strlcpy], [ PKG_CHECK_MODULES([libbsd], [libbsd]) ])
+
+# Checks for header files.
+AC_FUNC_ALLOCA
+AC_CHECK_HEADERS([inttypes.h libintl.h limits.h malloc.h stddef.h stdint.h stdlib.h string.h unistd.h])
+
+# Checks for typedefs, structures, and compiler characteristics.
+AC_C_INLINE
+AC_TYPE_INT16_T
+AC_TYPE_INT32_T
+AC_TYPE_INT8_T
+AC_TYPE_SIZE_T
+AC_TYPE_UINT16_T
+AC_TYPE_UINT32_T
+AC_TYPE_UINT8_T
+
+# Checks for library functions.
+AC_FUNC_MALLOC
+AC_FUNC_REALLOC
+AC_CHECK_FUNCS([memset realpath strdup strndup])
+
+AC_CONFIG_FILES([Makefile
+                 data/Makefile
+                 src/Makefile])
 AC_OUTPUT
diff --git a/src/Makefile.am b/src/Makefile.am
index a25dd09..159084f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -14,7 +14,7 @@ sermon_SOURCES = citations.c \
 				 utf8.c \
 				 xml.c \
 				 xslt.c
-sermon_LDADD = ${libxml2_LIBS} ${libxslt_LIBS}
+sermon_LDADD = ${libxml2_LIBS} ${libxslt_LIBS} ${libbsd_LIBS}
 CLEANFILES = sermon_lexer.c \
 			 sermon_parser.c \
 			 sermon_parser.h
diff --git a/src/sermon_lexer.l b/src/sermon_lexer.l
index 899ca6d..77a6225 100644
--- a/src/sermon_lexer.l
+++ b/src/sermon_lexer.l
@@ -1,5 +1,6 @@
 %{
 #include <string.h>
+#include "sermon.h"
 #include "sermon_parser.h"
 
 #ifdef LEXDEBUG