diff --git a/configure.ac b/configure.ac
index 3204869..43a804b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -783,6 +783,7 @@ esac
 
 case "x$enable_glx$enable_xlib_glx" in
 xyesyes)
+    PKG_CHECK_MODULES([XLIBGL], [x11 xext])
     DRIVER_DIRS="$DRIVER_DIRS x11"
     GALLIUM_WINSYS_DIRS="$GALLIUM_WINSYS_DIRS sw/xlib"
     GALLIUM_TARGET_DIRS="$GALLIUM_TARGET_DIRS libgl-xlib"
@@ -1521,7 +1522,7 @@ for plat in $egl_platforms; do
 		;;
 
 	x11)
-		PKG_CHECK_MODULES([XCB_DRI2], [x11-xcb xcb-dri2 >= 1.8 xcb-xfixes])
+		PKG_CHECK_MODULES([XCB_DRI2], [x11 x11-xcb xcb-dri2 >= 1.8 xcb-xfixes])
 
                 if test "x$enable_glx" = xyes; then
                         HAVE_EGL_DRIVER_GLX=1