diff --git a/ChangeLog b/ChangeLog
index 3e1de62240..262b030567 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun Dec 11 10:37:47 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* object.c (rb_check_to_int): new function to convert a VALUE to
+	  an Integer if possible, but returns nil instead of raising an
+	  exception otherwise.
+
 Sun Dec 11 10:34:39 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* process.c (rb_exit_status_code): extract from rb_f_exit_bang and
diff --git a/include/ruby/intern.h b/include/ruby/intern.h
index 675694179b..fbc9c49cfb 100644
--- a/include/ruby/intern.h
+++ b/include/ruby/intern.h
@@ -553,6 +553,7 @@ VALUE rb_check_convert_type(VALUE,int,const char*,const char*);
 VALUE rb_check_to_integer(VALUE, const char *);
 VALUE rb_check_to_float(VALUE);
 VALUE rb_to_int(VALUE);
+VALUE rb_check_to_int(VALUE);
 VALUE rb_Integer(VALUE);
 VALUE rb_to_float(VALUE);
 VALUE rb_Float(VALUE);
diff --git a/object.c b/object.c
index 4881cfd324..82fab4a812 100644
--- a/object.c
+++ b/object.c
@@ -2187,6 +2187,12 @@ rb_to_int(VALUE val)
     return rb_to_integer(val, "to_int");
 }
 
+VALUE
+rb_check_to_int(VALUE val)
+{
+    return rb_check_to_integer(val, "to_int");
+}
+
 static VALUE
 rb_convert_to_integer(VALUE val, int base)
 {