2 files changed, 25 insertions, 5 deletions
diff --git a/ext/psych/lib/psych/visitors/to_ruby.rb b/ext/psych/lib/psych/visitors/to_ruby.rb
index fd899f65a6..b76cd7d5ec 100644
--- a/ext/psych/lib/psych/visitors/to_ruby.rb
+++ b/ext/psych/lib/psych/visitors/to_ruby.rb
@@ -1,5 +1,9 @@
 require 'psych/scalar_scanner'
 
+unless defined?(Regexp::NOENCODING)
+  Regexp::NOENCODING = 32
+end
+
 module Psych
   module Visitors
     ###
diff --git a/ext/psych/lib/psych/visitors/yaml_tree.rb b/ext/psych/lib/psych/visitors/yaml_tree.rb
index 70db181a95..1f1acdbbcf 100644
--- a/ext/psych/lib/psych/visitors/yaml_tree.rb
+++ b/ext/psych/lib/psych/visitors/yaml_tree.rb
@@ -311,11 +311,27 @@ module Psych
       end
 
       private
-      def format_time time
-        if time.utc?
-          time.strftime("%Y-%m-%d %H:%M:%S.%9N Z")
-        else
-          time.strftime("%Y-%m-%d %H:%M:%S.%9N %:z")
+      # '%:z' was no defined until 1.9.3
+      if RUBY_VERSION < '1.9.3'
+        def format_time time
+          formatted = time.strftime("%Y-%m-%d %H:%M:%S.%9N")
+
+          if time.utc?
+            formatted += " Z"
+          else
+            zone = time.strftime('%z')
+            formatted += " #{zone[0,3]}:#{zone[3,5]}"
+          end
+
+          formatted
+        end
+      else
+        def format_time time
+          if time.utc?
+            time.strftime("%Y-%m-%d %H:%M:%S.%9N Z")
+          else
+            time.strftime("%Y-%m-%d %H:%M:%S.%9N %:z")
+          end
         end
       end