diff --git a/ChangeLog b/ChangeLog
index 327ac5a9..2631755c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2005-08-17  Adam Jackson  <ajax@freedesktop.org>
+
+	* configure.ac:
+	* x11.pc.in:
+	Add xthreadlib variable to x11.pc.  Bump to 0.99.1.
+
 2005-07-14  Keith Packard  <keithp@keithp.com>
 
 	* Makefile.am:
diff --git a/configure.ac b/configure.ac
index 0bfa732c..9cfd3424 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,7 +3,7 @@
 
 AC_PREREQ(2.57)
 AC_INIT([libX11],
-        0.99.0,
+        0.99.1,
         [https://bugs.freedesktop.org/enter_bug.cgi?product=xorg],
         libX11)
 AC_CONFIG_SRCDIR([Makefile.am])
@@ -139,6 +139,15 @@ esac
 AC_SUBST(XTHREADS)
 AC_SUBST(XUSE_MTSAFE_API)
 
+dnl XXX incomplete, please fill this in
+if test x$xthreads == xyes ; then
+    case $host_os in
+    linux*)
+        XTHREADLIB=-lpthread ;;
+    esac
+fi
+AC_SUBST(XTHREADLIB)
+
 AC_CHECK_LIB(Xdmcp, XdmcpWrap, [xdmauth="yes"], [xdmauth="no"], [$XDMCP_LIBS])
 
 case x$xdmauth in
diff --git a/x11.pc.in b/x11.pc.in
index 40f581df..2358eb4b 100644
--- a/x11.pc.in
+++ b/x11.pc.in
@@ -3,6 +3,8 @@ exec_prefix=@exec_prefix@
 libdir=@libdir@
 includedir=@includedir@
 
+xthreadlib=@XTHREADLIB@
+
 Name: X11
 Description: X Library
 Version: @PACKAGE_VERSION@