diff --git a/aclocal.m4 b/aclocal.m4
index 51da0dfff122d15268073a1df59fadabcd28d7e9..8cec31773228c7b9e7128274f9d91935adb4e65b 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1,4 +1,4 @@
-dnl $Id: aclocal.m4,v 1.50 2000/06/15 20:22:53 panne Exp $
+dnl $Id: aclocal.m4,v 1.51 2000/06/29 13:40:17 simonmar Exp $
 dnl 
 dnl Extra autoconf macros for the Glasgow fptools
 dnl
@@ -73,6 +73,25 @@ fi
 ])
 
 
+dnl *** Does libc contain GNU regex? ***
+dnl 
+AC_DEFUN(FPTOOLS_REGEX_IN_LIBC,
+[AC_CACHE_CHECK([for GNU regex in libc], fptools_cv_have_regex,
+[AC_TRY_LINK([#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <regex.h>
+],[ struct re_pattern_buffer patbuf; re_compile_pattern("",0,&patbuf); ],
+fptools_cv_have_regex=yes, fptools_cv_have_regex=no)])
+if test "$fptools_cv_have_regex" = yes; then
+	HaveRegex=YES
+else
+	HaveRegex=NO
+fi
+AC_SUBST(HaveRegex)
+])
+
+
 dnl ** check for leading underscores in symbol names
 dnl 
 dnl Test for determining whether symbol names have a leading
diff --git a/configure.in b/configure.in
index 6f07d0772477ad89209d423b7070a785ff2ad249..a33ec32b5a04102894db570062649c65bec41efc 100644
--- a/configure.in
+++ b/configure.in
@@ -721,6 +721,9 @@ AC_CHECK_LIB(gmp,  mpz_fdiv_qr, HaveLibGmp=YES; LibGmp=gmp,
 AC_SUBST(HaveLibGmp)
 AC_SUBST(LibGmp)
 
+dnl ** check whether this machine has GNU regex in libc.
+FPTOOLS_REGEX_IN_LIBC
+
 dnl ** check whether this machine has BFD and liberty installed (used for debugging)
 dnl    the order of these tests matters: bfd needs liberty
 AC_CHECK_LIB(iberty, xmalloc)
diff --git a/mk/config.mk.in b/mk/config.mk.in
index 66fe0936022e584df41d0ca37e60e880bc60ceaa..7647f2654d6d7d8a5ebfae8e23d3e8b167845708 100644
--- a/mk/config.mk.in
+++ b/mk/config.mk.in
@@ -542,6 +542,12 @@ endif
 HaveLibGmp	= @HaveLibGmp@
 LibGmp		= @LibGmp@
 
+#-----------------------------------------------------------------------------
+# Regex library 
+# (if present in libc use that one, otherwise use the one in the tree)
+#
+HaveRegex	= @HaveRegex@
+
 #-----------------------------------------------------------------------------
 # Flex