2 files changed, 6 insertions, 1 deletions
diff --git a/ext/psych/lib/psych.rb b/ext/psych/lib/psych.rb
index 16602ef221..a582f56eb1 100644
--- a/ext/psych/lib/psych.rb
+++ b/ext/psych/lib/psych.rb
@@ -241,6 +241,5 @@ module Psych
     attr_accessor :dump_tags
     attr_accessor :domain_types
   end
-
   # :startdoc:
 end
diff --git a/ext/psych/lib/psych/deprecated.rb b/ext/psych/lib/psych/deprecated.rb
index 093f145302..fdff46845d 100644
--- a/ext/psych/lib/psych/deprecated.rb
+++ b/ext/psych/lib/psych/deprecated.rb
@@ -30,6 +30,12 @@ module Psych
     list.each(&block)
   end
 
+  def self.detect_implicit thing
+    warn "#{caller[0]}: detect_implicit is deprecated" if $VERBOSE
+    return '' unless String === thing
+    return 'null' if '' == thing
+    ScalarScanner.new.tokenize(thing).class.name.downcase
+  end
 end
 
 class Object