diff --git a/changes-5.1.html b/changes-5.1.html
index 9bf10aca2..e9d159648 100644
--- a/changes-5.1.html
+++ b/changes-5.1.html
@@ -17,7 +17,9 @@ xb
Yap-5.1.3:
-- FIXED: true_file_name/3 was totally broken (obs from Nicos Agelopoulos).
+- NEW: verbose prolog_flag fixes silent (obs from Nicos
+Angelopoulos).
+- FIXED: true_file_name/3 was totally broken (obs from Nicos Angelopoulos).
- FIXED: Environment variables should only be seen at the beginning
of the file (obs from Samir Genaim.)
- FIXED: [ ] should be processed by parser, not by scanner (obs
diff --git a/docs/yap.tex b/docs/yap.tex
index c654712ef..0fda315cb 100644
--- a/docs/yap.tex
+++ b/docs/yap.tex
@@ -7831,6 +7831,14 @@ the current @code{user_output} stream.
By default, the @code{user_output} stream is set to a stream
corresponding to the Unix @code{stdout} stream.
+@item verbose
+@findex verbose (yap_flag/2 option)
+@*
+If @code{normal} allow printing of informational and banner messages,
+such as the ones that are printed when consulting. If @code{silent}
+disable printing these messages. It is @code{normal} by default except if
+YAP is booted with the @code{-L} flag.
+
@item version
@findex version (yap_flag/2 option)
@* Read-only flag that returns an atom with the current version of
diff --git a/pl/directives.yap b/pl/directives.yap
index 461477b06..71b6690c6 100644
--- a/pl/directives.yap
+++ b/pl/directives.yap
@@ -322,6 +322,14 @@ yap_flag(informational_messages,off) :- !, set_value('$verbose',off).
yap_flag(informational_messages,X) :-
'$do_error'(domain_error(flag_value,informational_messages+X),yap_flag(informational_messages,X)).
+yap_flag(verbose,X) :- var(X), !,
+ get_value('$verbose',X0),
+ (X0 == on -> X = normal ; X = silent).
+yap_flag(verbose,normal) :- !, set_value('$verbose',on).
+yap_flag(verbose,silent) :- !, set_value('$verbose',off).
+yap_flag(verbose,X) :-
+ '$do_error'(domain_error(flag_value,verbose+X),yap_flag(verbose,X)).
+
yap_flag(integer_rounding_function,X) :-
var(X), !,
'$access_yap_flags'(2, X1),
@@ -859,6 +867,7 @@ yap_flag(dialect,yap).
V = user_input ;
V = user_output ;
V = variable_names_may_end_with_quotes ;
+ V = verbose ;
V = verbose_auto_load ;
V = version ;
V = version_data ;