diff --git a/ChangeLog b/ChangeLog
index 9e7b6bb8d..f78667dc3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2013-02-06  Werner Lemberg  <wl@gnu.org>
+
+	* src/truetype/ttobjs.c (tt_size_run_prep): Reset reference points.
+
+	Up to now, we simply took a snapshot of the Graphics State after the
+	`prep' table has been executed, and right before a glyph's bytecode
+	was run it got reloaded.  However, as Greg Hitchcock has told us in
+	private communication, reference points get reset to zero in the MS
+	rasterizer and we follow in due course.  While reasonable, this is
+	undocumented behaviour.
+
+	Most notably, this fixes the rendering of Arial's `x' glyph in
+	subpixel hinting mode.
+
 2013-02-05  Werner Lemberg  <wl@gnu.org>
 
 	[truetype] A better fix for Savannah bug #38211.
diff --git a/src/truetype/ttobjs.c b/src/truetype/ttobjs.c
index ca4a377ee..9b828c3ba 100644
--- a/src/truetype/ttobjs.c
+++ b/src/truetype/ttobjs.c
@@ -878,6 +878,11 @@
     else
       error = TT_Err_Ok;
 
+    /* UNDOCUMENTED!  Reference points are reset to zero. */
+    exec->GS.rp0 = 0;
+    exec->GS.rp1 = 0;
+    exec->GS.rp2 = 0;
+
     /* save as default graphics state */
     size->GS = exec->GS;