diff --git a/fog.gemspec b/fog.gemspec
index 2f6e0ba9f..3cd571865 100644
--- a/fog.gemspec
+++ b/fog.gemspec
@@ -50,6 +50,7 @@ Gem::Specification.new do |s|
   s.add_dependency('net-ssh', '>=2.1.3')
   s.add_dependency('nokogiri', '~>1.5')
   s.add_dependency('ruby-hmac')
+  s.add_dependency('unicode', "~> 0.4.4")
 
   ## List your development dependencies here. Development dependencies are
   ## those that are only needed during development
diff --git a/lib/fog/aws.rb b/lib/fog/aws.rb
index afe2fe2b8..5054940aa 100644
--- a/lib/fog/aws.rb
+++ b/lib/fog/aws.rb
@@ -1,6 +1,7 @@
 require 'fog/core'
 require 'fog/aws/credential_fetcher'
 require 'fog/aws/signaturev4'
+require 'unicode'
 module Fog
   module AWS
     extend Fog::Provider
@@ -85,7 +86,8 @@ module Fog
     end
 
     def self.escape(string)
-      string.gsub(/([^a-zA-Z0-9_.\-~]+)/) {
+      string = Unicode::normalize_C(string)
+      string.gsub(/([^a-zA-Z0-9_.\-~\/]+)/) {
         "%" + $1.unpack("H2" * $1.bytesize).join("%").upcase
       }
     end
diff --git a/tests/aws/signed_params_tests.rb b/tests/aws/signed_params_tests.rb
index 1df3950de..d1e3f124c 100644
--- a/tests/aws/signed_params_tests.rb
+++ b/tests/aws/signed_params_tests.rb
@@ -2,4 +2,16 @@
 
 Shindo.tests('AWS | signed_params', ['aws']) do
   returns( Fog::AWS.escape( "'Stöp!' said Fred_-~." ) ) { "%27St%C3%B6p%21%27%20said%20Fred_-~." }
+
+  tests('Keys can contain a hierarchical prefix which should not be escaped') do
+    returns( Fog::AWS.escape( "key/with/prefix" ) ) { "key/with/prefix" }
+  end
+
+  tests('Keys should be canonicalised using Unicode NFC') do
+    returns( Fog::AWS.escape( ["00E9".to_i(16)].pack("U*") ) ) { "%C3%A9" }
+
+    tests('Characters with combining mark should be combined and then escaped') do
+      returns( Fog::AWS.escape( ["0065".to_i(16), "0301".to_i(16)].pack("U*") ) ) { "%C3%A9" }
+    end
+  end
 end