diff --git a/ChangeLog b/ChangeLog
index 532db76f7..81168cc17 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2004-05-01  Werner Koch  <wk@gnupg.org>
+
+	* acinclude.m4 (ac_pipe_works): Fixed BRE syntax \? -> \{0,1\}.
+	Reported by Todd Vierling.
+
 2004-03-29  Werner Koch  <wk@gnupg.org>
 
 	Released 1.2.5rc1.
diff --git a/acinclude.m4 b/acinclude.m4
index 4e18c2605..68a1ae034 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -587,10 +587,10 @@ extern "C" {
 #endif
 
 EOF
-        # Now generate the symbol file.
-        sed 's/^.* _\?\(.*\)$/extern char \1;/' < "$ac_nlist" >> conftest.c
+      # Now generate the symbol file.
+      sed 's/^.* _\{0,1\}\(.*\)$/extern char \1;/' < "$ac_nlist" >> conftest.c
 
-        cat <<EOF >> conftest.c
+      cat <<EOF >> conftest.c
 #if defined (__STDC__) && __STDC__
 # define __ptr_t void *
 #else
@@ -610,7 +610,7 @@ dld_preloaded_symbols[] =
 changequote([,])dnl
 {
 EOF
-        sed 's/^_\?\(.*\) _\?\(.*\)$/  {"\1", (__ptr_t) \&\2},/' < "$ac_nlist" >> conftest.c
+        sed 's/^_\{0,1\}/\(.*\) _\{0,1\}\(.*\)$/  {"\1", (__ptr_t) \&\2},/' < "$ac_nlist" >> conftest.c
         cat <<\EOF >> conftest.c
   {0, (__ptr_t) 0}
 };