diff -r fbb3c68a8d3c -r 4f9f61f9b535 src/HOL/Proofs/Lambda/Lambda.thy
--- a/src/HOL/Proofs/Lambda/Lambda.thy	Fri Feb 17 11:24:39 2012 +0100
+++ b/src/HOL/Proofs/Lambda/Lambda.thy	Fri Feb 17 15:42:26 2012 +0100
@@ -7,7 +7,7 @@
 
 theory Lambda imports Main begin
 
-declare [[syntax_ambiguity = ignore]]
+declare [[syntax_ambiguity_warning = false]]
 
 
 subsection {* Lambda-terms in de Bruijn notation and substitution *}