diff --git a/grep.changes b/grep.changes
index bb32af2..c356cf5 100644
--- a/grep.changes
+++ b/grep.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Tue Jan 21 10:57:16 UTC 2020 - Andreas Schwab <schwab@suse.de>
+
+- Switch back to system regex to avoid undefined behaviour
+
 -------------------------------------------------------------------
 Sun Jan  5 10:59:44 UTC 2020 - Andreas Stieger <andreas.stieger@gmx.de>
 
diff --git a/grep.spec b/grep.spec
index 0e1e7ba..9914ec7 100644
--- a/grep.spec
+++ b/grep.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package grep
 #
-# Copyright (c) 2020 SUSE LINUX GmbH, Nuernberg, Germany.
+# Copyright (c) 2020 SUSE LLC
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -22,7 +22,7 @@ Release:        0
 Summary:        Print lines matching a pattern
 License:        GPL-3.0-or-later
 Group:          Productivity/Text/Utilities
-Url:            https://www.gnu.org/software/grep/
+URL:            https://www.gnu.org/software/grep/
 Source0:        https://ftp.gnu.org/gnu/%{name}/%{name}-%{version}.tar.xz
 Source2:        https://ftp.gnu.org/gnu/%{name}/%{name}-%{version}.tar.xz.sig
 Source3:        https://savannah.gnu.org/project/memberlist-gpgkeys.php?group=grep&download=1#/%{name}.keyring
@@ -45,6 +45,7 @@ match to a specified pattern.  By default, grep prints the matching lines.
 %build
 %configure \
   --disable-silent-rules \
+  --without-included-regex \
   %{nil}
 %if 0%{?do_profiling}
   make %{?_smp_mflags} CFLAGS="%{optflags} %{cflags_profile_generate} -fno-profile-values"