diff --git a/test/protocol/http/header/accept.rb b/test/protocol/http/header/accept.rb
index d9f878e..d650b9f 100644
--- a/test/protocol/http/header/accept.rb
+++ b/test/protocol/http/header/accept.rb
@@ -11,6 +11,12 @@
 		expect(media_range.quality_factor).to be == 1.0
 	end
 	
+	it "compares by quality factor" do
+		high = subject.new("text", "html", {"q" => "0.9"})
+		low = subject.new("text", "plain", {"q" => "0.5"})
+		expect(high <=> low).to be == -1
+	end
+	
 	with "#to_s" do
 		it "can convert to string" do
 			media_range = subject.new("text", "plain", {"q" => "0.5"})
diff --git a/test/protocol/http/header/accept_charset.rb b/test/protocol/http/header/accept_charset.rb
index 839eb10..b89d8e1 100644
--- a/test/protocol/http/header/accept_charset.rb
+++ b/test/protocol/http/header/accept_charset.rb
@@ -10,6 +10,12 @@
 		charset = subject.new("utf-8", nil)
 		expect(charset.quality_factor).to be == 1.0
 	end
+	
+	it "compares by quality factor" do
+		high = subject.new("utf-8", "0.9")
+		low = subject.new("iso-8859-1", "0.5")
+		expect(high <=> low).to be == -1
+	end
 end
 
 describe Protocol::HTTP::Header::AcceptCharset do
diff --git a/test/protocol/http/header/accept_encoding.rb b/test/protocol/http/header/accept_encoding.rb
index 6269d56..836e569 100644
--- a/test/protocol/http/header/accept_encoding.rb
+++ b/test/protocol/http/header/accept_encoding.rb
@@ -10,6 +10,12 @@
 		encoding = subject.new("utf-8", nil)
 		expect(encoding.quality_factor).to be == 1.0
 	end
+	
+	it "compares by quality factor" do
+		high = subject.new("gzip", "0.9")
+		low = subject.new("deflate", "0.5")
+		expect(high <=> low).to be == -1
+	end
 end
 
 describe Protocol::HTTP::Header::AcceptEncoding do
diff --git a/test/protocol/http/header/accept_language.rb b/test/protocol/http/header/accept_language.rb
index cd657f6..6bb3e11 100644
--- a/test/protocol/http/header/accept_language.rb
+++ b/test/protocol/http/header/accept_language.rb
@@ -10,6 +10,12 @@
 		language = subject.new("utf-8", nil)
 		expect(language.quality_factor).to be == 1.0
 	end
+	
+	it "compares by quality factor" do
+		high = subject.new("en", "0.9")
+		low = subject.new("fr", "0.5")
+		expect(high <=> low).to be == -1
+	end
 end
 
 describe Protocol::HTTP::Header::AcceptLanguage do