diff --git a/CHANGELOG.rdoc b/CHANGELOG.rdoc
index 1b54ddf39..60a34c23d 100644
--- a/CHANGELOG.rdoc
+++ b/CHANGELOG.rdoc
@@ -1,5 +1,7 @@
 == HEAD
 
+* Fix failing spec Issue 453 on Ruby 1.9.3
+
 == Version 2.4.4 - Wed Mar 14 22:44:00 +1100 2012 Mikel Lindsaar <mikel@reinteractive.net>
 
 * Fix security vulnerability allowing command line exploit when using file delivery method
diff --git a/Gemfile b/Gemfile
index 35cfb16d1..d6c19113d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,17 +1,20 @@
 source :rubygems
 
-gem "activesupport", ">= 2.3.6"
+gem 'activesupport', '>= 2.3.6' if RUBY_VERSION >= '1.9.3'
+gem 'activesupport', '>= 2.3.6', '< 4.0.0' if RUBY_VERSION < '1.9.3'
 gem "tlsmail" if RUBY_VERSION <= '1.8.6'
 gem "mime-types", "~> 1.16"
 gem "treetop", "~> 1.4.10"
-gem "i18n", ">= 0.4.0"
+gem 'i18n', '>= 0.4.0' if RUBY_VERSION >= '1.9.3'
+gem 'i18n', '>= 0.4.0', '< 0.7.0' if RUBY_VERSION < '1.9.3'
 
 if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'jruby'
   gem 'jruby-openssl'
 end
 
 group :test do
-  gem "rake",       "> 0.8.7"
+  gem 'rake', '> 0.8.7' if RUBY_VERSION >= '1.9.3'
+  gem 'rake', '> 0.8.7', '< 11.0.1' if RUBY_VERSION < '1.9.3'
   gem "rspec",      "~> 2.8.0"
   case
   when defined?(RUBY_ENGINE) && RUBY_ENGINE == 'rbx'
diff --git a/lib/mail/version_specific/ruby_1_8.rb b/lib/mail/version_specific/ruby_1_8.rb
index 1cb73c704..48790984b 100644
--- a/lib/mail/version_specific/ruby_1_8.rb
+++ b/lib/mail/version_specific/ruby_1_8.rb
@@ -80,7 +80,10 @@ def Ruby18.q_value_decode(str)
       match = str.match(/\=\?(.+)?\?[Qq]\?(.+)?\?\=/m)
       if match
         encoding = match[1]
-        str = Encodings::QuotedPrintable.decode(match[2].gsub(/_/, '=20'))
+        string = match[2].gsub(/_/, '=20')
+        # Remove trailing = if it exists in a Q encoding
+        string = string.sub(/\=$/, '')
+        str = Encodings::QuotedPrintable.decode(string)
       end
       str
     end
diff --git a/lib/mail/version_specific/ruby_1_9.rb b/lib/mail/version_specific/ruby_1_9.rb
index 0eb3806bd..cb210d9d0 100644
--- a/lib/mail/version_specific/ruby_1_9.rb
+++ b/lib/mail/version_specific/ruby_1_9.rb
@@ -68,7 +68,10 @@ def Ruby19.q_value_decode(str)
       match = str.match(/\=\?(.+)?\?[Qq]\?(.+)?\?\=/m)
       if match
         encoding = match[1]
-        str = Encodings::QuotedPrintable.decode(match[2].gsub(/_/, '=20'))
+        string = match[2].gsub(/_/, '=20')
+        # Remove trailing = if it exists in a Q encoding
+        string = string.sub(/\=$/, '')
+        str = Encodings::QuotedPrintable.decode(string)
         str.force_encoding(fix_encoding(encoding))
       end
       decoded = str.encode("utf-8", :invalid => :replace, :replace => "")
diff --git a/mail.gemspec b/mail.gemspec
index ffaf02534..cc5ddce91 100644
--- a/mail.gemspec
+++ b/mail.gemspec
@@ -17,7 +17,8 @@ Gem::Specification.new do |s|
 
   s.add_dependency('mime-types', "~> 1.16")
   s.add_dependency('treetop', '~> 1.4.8')
-  s.add_dependency('i18n', '>= 0.4.0')
+  s.add_dependency('i18n', '>= 0.4.0') if RUBY_VERSION >= '1.9.3'
+  s.add_dependency('i18n', '>= 0.4.0', '< 0.7.0') if RUBY_VERSION < '1.9.3'
   s.add_dependency('jruby-openssl') if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'jruby'
   s.add_dependency('tlsmail', '~> 0.0.1') if RUBY_VERSION == '1.8.6'
 
diff --git a/spec/mail/encodings_spec.rb b/spec/mail/encodings_spec.rb
index e33ebb414..6c4aa698f 100644
--- a/spec/mail/encodings_spec.rb
+++ b/spec/mail/encodings_spec.rb
@@ -609,6 +609,12 @@
         b.should eq expected
       end
 
+      it "should unquote Shift_JIS QP with trailing =" do
+        a = "=?Shift_JIS?Q?=93=FA=96{=8C=EA=?="
+        b = Mail::Encodings.unquote_and_convert_to(a, 'utf-8')
+        b.should eq "日本語"
+      end
+
       it "should unquote multiple strings in the middle of the text" do
         a = "=?Shift_JIS?Q?=93=FA=96{=8C=EA=?= <a@example.com>, =?Shift_JIS?Q?=93=FA=96{=8C=EA=?= <b@example.com>"
         b = Mail::Encodings.unquote_and_convert_to(a, 'utf-8')
diff --git a/spec/mail/message_spec.rb b/spec/mail/message_spec.rb
index a19e1a40d..d9f45c5ab 100644
--- a/spec/mail/message_spec.rb
+++ b/spec/mail/message_spec.rb
@@ -123,6 +123,10 @@ def basic_email
 
     describe "YAML serialization" do
       before(:each) do
+        # Ensure specs don't randomly fail due to messages being generated 1 second apart
+        time = DateTime.now
+        DateTime.stub(:now).and_return(time)
+
         @yaml_mail = Mail::Message.new(:to => 'someone@somewhere.com',
                                   :cc => 'someoneelse@somewhere.com',
                                   :bcc => 'someonesecret@somewhere.com',