--- a/configure.ac	Sat Aug 13 18:40:40 2005 +0000
+++ b/configure.ac	Sat Aug 13 22:09:34 2005 +0000
@@ -43,7 +43,7 @@
 dnl Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
-AC_CHECK_HEADERS(fcntl.h sys/time.h unistd.h locale.h signal.h stdint.h)
+AC_CHECK_HEADERS(fcntl.h sys/time.h unistd.h locale.h signal.h stdint.h regex.h)
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST