diff --git a/lib/protocol/http1/connection.rb b/lib/protocol/http1/connection.rb
index 18eae64..4adecd9 100644
--- a/lib/protocol/http1/connection.rb
+++ b/lib/protocol/http1/connection.rb
@@ -43,7 +43,7 @@ module HTTP1
 		HEADER = /\A(#{FIELD_NAME}):#{OWS}(?:(#{FIELD_VALUE})#{OWS})?\z/.freeze
 		
 		VALID_FIELD_NAME = /\A#{FIELD_NAME}\z/.freeze
-		VALID_FIELD_VALUE = /\A#{FIELD_VALUE}\z/.freeze
+		VALID_FIELD_VALUE = /\A#{FIELD_VALUE}?\z/.freeze
 		
 		DEFAULT_MAXIMUM_LINE_LENGTH = 8192
 		
diff --git a/test/protocol/http1/connection/headers.rb b/test/protocol/http1/connection/headers.rb
index 5b1e8cf..2c7be24 100644
--- a/test/protocol/http1/connection/headers.rb
+++ b/test/protocol/http1/connection/headers.rb
@@ -9,112 +9,203 @@
 describe Protocol::HTTP1::Connection do
 	include_context ConnectionContext
 	
-	let(:headers) {Array.new}
+	with "#write_response" do
+		before do
+			server.open!
+		end
 
-	before do
-		client.stream.write "GET / HTTP/1.1\r\nHost: localhost\r\n#{headers.join("\r\n")}\r\n\r\n"
-		client.stream.close
-	end
+		def validate_headers!(expected_headers = self.headers)
+			server.write_empty_body
+			client.open!
+
+			version, status, reason, headers, body = client.read_response("GET")
+
+			expect(headers).to be == headers
+		end
 
-	with "header that contains tab characters" do
-		let(:headers) {[
-			"user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) \t\t\tChrome/55.0.2883.95 Safari/537.36"
-		]}
+		with "a content-type header" do
+			let(:headers) {{"content-type" => "text/plain"}}
 
-		it "can parse the header" do
-			authority, method, target, version, headers, body = server.read_request
+			it "can parse the header" do
+				server.write_response("HTTP/1.1", 200, headers)
 
-			expect(headers).to have_keys(
-				"user-agent" => be == "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) \t\t\tChrome/55.0.2883.95 Safari/537.36"
-			)
+				validate_headers!
+			end
 		end
-	end
 
-	with "header that contains obsolete folding whitespace" do
-		let(:headers) {[
-			"user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko)\n\tChrome/55.0.2883.95 Safari/537.36"
-		]}
+		with "an empty header" do
+			let(:headers) {{"nothing" => ""}}
 
-		it "rejects the request" do
-			expect do
-				server.read_request
-			end.to raise_exception(Protocol::HTTP1::BadHeader)
+			it "can parse the header" do
+				server.write_response("HTTP/1.1", 200, headers)
+				
+				validate_headers!
+			end
 		end
-	end
 
-	with "header that contains invalid characters" do
-		let(:headers) {[
-			"user-agent: Mozilla\x00Hacker Browser"
-		]}
+		with "a header that contains tab characters" do
+			let(:headers) {{"user-agent" => "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) \t\t\tChrome/55.0.2883.95 Safari/537.36"}}
+
+			it "can parse the header" do
+				server.write_response("HTTP/1.1", 200, headers)
 
-		it "rejects the request" do
-			expect do
-				server.read_request
-			end.to raise_exception(Protocol::HTTP1::BadHeader)
+				validate_headers!
+			end
 		end
-	end
 
-	with "header that contains invalid high characters" do
-		let(:headers) {[
-			"user-agent: Mozilla\x7FHacker Browser"
-		]}
+		with "a header that contains obsolete folding whitespace" do
+			let(:headers) {{"user-agent" => "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko)\n\tChrome/55.0.2883.95 Safari/537.36"}}
+
+			it "rejects the response" do
+				expect do
+					server.write_response("HTTP/1.1", 200, headers)
+				end.to raise_exception(Protocol::HTTP1::BadHeader)
+			end
+		end
 
-		it "allows the request" do
-			authority, method, target, version, headers, body = server.read_request
+		with "a header that contains invalid characters" do
+			let(:headers) {{"user-agent" => "Mozilla\x00Hacker Browser"}}
 
-			expect(headers).to have_keys(
-				"user-agent" => be == "Mozilla\x7FHacker Browser"
-			)
+			it "rejects the response" do
+				expect do
+					server.write_response("HTTP/1.1", 200, headers)
+				end.to raise_exception(Protocol::HTTP1::BadHeader)
+			end
 		end
-	end
 
-	with "header that contains null character" do
-		let(:headers) {[
-			"user-agent: Mozilla\x00Hacker Browser"
-		]}
+		with "a header that contains invalid high characters" do
+			let(:headers) {{"user-agent" => "Mozilla\x7FHacker Browser"}}
+
+			it "allows the response" do
+				server.write_response("HTTP/1.1", 200, headers)
 
-		it "rejects the request" do
-			expect do
-				server.read_request
-			end.to raise_exception(Protocol::HTTP1::BadHeader)
+				validate_headers!
+			end
 		end
 	end
 
-	with "header that has empty value" do
-		let(:headers) {[
-			"user-agent: "
-		]}
+	with "#read_request" do
+		let(:headers) {Array.new}
+
+		before do
+			client.stream.write "GET / HTTP/1.1\r\nHost: localhost\r\n#{headers.join("\r\n")}\r\n\r\n"
+			client.stream.close
+		end
+
+		with "a header that contains tab characters" do
+			let(:headers) {[
+				"user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) \t\t\tChrome/55.0.2883.95 Safari/537.36"
+			]}
 
-		it "can parse the header" do
-			authority, method, target, version, headers, body = server.read_request
+			it "can parse the header" do
+				authority, method, target, version, headers, body = server.read_request
 
-			expect(headers).to have_keys(
-				"user-agent" => be == ""
-			)
+				expect(headers).to have_keys(
+					"user-agent" => be == "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) \t\t\tChrome/55.0.2883.95 Safari/537.36"
+				)
+			end
 		end
-	end
 
-	with "header that has invalid name" do
-		let(:headers) {[
-			"invalid name: value"
-		]}
+		with "a header that contains obsolete folding whitespace" do
+			let(:headers) {[
+				"user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko)\n\tChrome/55.0.2883.95 Safari/537.36"
+			]}
 
-		it "rejects the request" do
-			expect do
-				server.read_request
-			end.to raise_exception(Protocol::HTTP1::BadHeader)
+			it "rejects the request" do
+				expect do
+					server.read_request
+				end.to raise_exception(Protocol::HTTP1::BadHeader)
+			end
+		end
+
+		with "a header that contains invalid characters" do
+			let(:headers) {[
+				"user-agent: Mozilla\x00Hacker Browser"
+			]}
+
+			it "rejects the request" do
+				expect do
+					server.read_request
+				end.to raise_exception(Protocol::HTTP1::BadHeader)
+			end
+		end
+
+		with "a header that contains invalid high characters" do
+			let(:headers) {[
+				"user-agent: Mozilla\x7FHacker Browser"
+			]}
+
+			it "allows the request" do
+				authority, method, target, version, headers, body = server.read_request
+
+				expect(headers).to have_keys(
+					"user-agent" => be == "Mozilla\x7FHacker Browser"
+				)
+			end
+		end
+
+		with "a header that contains null character" do
+			let(:headers) {[
+				"user-agent: Mozilla\x00Hacker Browser"
+			]}
+
+			it "rejects the request" do
+				expect do
+					server.read_request
+				end.to raise_exception(Protocol::HTTP1::BadHeader)
+			end
+		end
+
+		with "a header that has empty value but includes optional whitespace" do
+			let(:headers) {[
+				"user-agent: "
+			]}
+
+			it "can parse the header" do
+				authority, method, target, version, headers, body = server.read_request
+
+				expect(headers).to have_keys(
+					"user-agent" => be == ""
+				)
+			end
+		end
+
+		with "a header that has empty value" do
+			let(:headers) {[
+				"user-agent:"
+			]}
+
+			it "can parse the header" do
+				authority, method, target, version, headers, body = server.read_request
+
+				expect(headers).to have_keys(
+					"user-agent" => be == ""
+				)
+			end
+		end
+
+		with "a header that has invalid name" do
+			let(:headers) {[
+				"invalid name: value"
+			]}
+
+			it "rejects the request" do
+				expect do
+					server.read_request
+				end.to raise_exception(Protocol::HTTP1::BadHeader)
+			end
 		end
-	end
 
-	with "header that has empty name" do
-		let(:headers) {[
-			": value"
-		]}
+		with "a header that has empty name" do
+			let(:headers) {[
+				": value"
+			]}
 
-		it "rejects the request" do
-			expect do
-				server.read_request
-			end.to raise_exception(Protocol::HTTP1::BadHeader)
+			it "rejects the request" do
+				expect do
+					server.read_request
+				end.to raise_exception(Protocol::HTTP1::BadHeader)
+			end
 		end
 	end
 end