diff -r 00b2b6716ed8 -r 23533273220a src/Pure/ML/install_pp_polyml-5.3.ML
--- a/src/Pure/ML/install_pp_polyml-5.3.ML	Wed Dec 29 18:18:42 2010 +0100
+++ b/src/Pure/ML/install_pp_polyml-5.3.ML	Wed Dec 29 20:41:33 2010 +0100
@@ -4,6 +4,9 @@
 Extra toplevel pretty-printing for Poly/ML 5.3.0.
 *)
 
+PolyML.addPrettyPrinter (fn depth => fn _ => fn str =>
+  ml_pretty (Pretty.to_ML (ML_Syntax.pretty_string (depth * 100) str)));
+
 PolyML.addPrettyPrinter (fn depth => fn pretty => fn var =>
   pretty (Synchronized.value var, depth));