diff --git a/.gitignore b/.gitignore
index b663d88..5939e9c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 aclocal.m4
 autom4te.cache/
+autoscan.log
 config.guess
 config.h
 config.h.in
@@ -8,6 +9,7 @@ config.log
 config.status
 config.sub
 configure
+configure.scan
 contrib/Makefile
 contrib/Makefile.in
 depcomp
diff --git a/configure.ac b/configure.ac
index 0894f27..89d285e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,24 +23,38 @@ AC_PROG_LIBTOOL
 LT_INIT
 
 # Checks for header files.
-
-AC_CHECK_HEADERS([arpa/inet.h \
+AC_CHECK_HEADERS([\
+	arpa/inet.h \
 	fcntl.h \
+	langinfo.h \
 	libintl.h \
 	netinet/in.h \
+	stddef.h \
 	stdlib.h \
 	string.h \
 	strings.h \
 	sys/socket.h \
-	unistd.h])
+	unistd.h \
+])
 
 # Checks for typedefs, structures, and compiler characteristics.
+AC_C_INLINE
 AC_HEADER_STDBOOL
 AC_TYPE_SIZE_T
+AC_TYPE_UINT32_T
 
 # Checks for library functions.
 AC_FUNC_MALLOC
-AC_CHECK_FUNCS([inet_ntoa memset strerror strstr strdup])
+AC_FUNC_REALLOC
+AC_CHECK_FUNCS([\
+	inet_ntoa \
+	memset \
+	nl_langinfo \
+	strdup \
+	strerror \
+	strrchr \
+	strstr \
+])
 
 AC_CONFIG_FILES([Makefile
 		 man/Makefile