diff --git a/spec/websocket_handler_spec.cr b/spec/websocket_handler_spec.cr
index 5f2974df..b07c91b1 100644
--- a/spec/websocket_handler_spec.cr
+++ b/spec/websocket_handler_spec.cr
@@ -25,27 +25,29 @@ describe "Kemal::WebSocketHandler" do
     ws "/" { |socket, context| socket.send("Match") }
     ws "/no_match" { |socket, context| socket.send "No Match" }
     headers = HTTP::Headers{
-      "Upgrade"           => "websocket",
-      "Connection"        => "Upgrade",
-      "Sec-WebSocket-Key" => "dGhlIHNhbXBsZSBub25jZQ==",
+      "Upgrade"               => "websocket",
+      "Connection"            => "Upgrade",
+      "Sec-WebSocket-Key"     => "dGhlIHNhbXBsZSBub25jZQ==",
+      "Sec-WebSocket-Version" => "13",
     }
     request = HTTP::Request.new("GET", "/", headers)
 
     io_with_context = create_ws_request_and_return_io(handler, request)
-    io_with_context.to_s.should eq("HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-Websocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=\r\n\r\n\x81\u0005Match")
+    io_with_context.to_s.should eq("HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=\r\n\r\n\x81\u0005Match")
   end
 
   it "fetches named url parameters" do
     handler = Kemal::WebSocketHandler::INSTANCE
     ws "/:id" { |s, c| c.params.url["id"] }
     headers = HTTP::Headers{
-      "Upgrade"           => "websocket",
-      "Connection"        => "Upgrade",
-      "Sec-WebSocket-Key" => "dGhlIHNhbXBsZSBub25jZQ==",
+      "Upgrade"               => "websocket",
+      "Connection"            => "Upgrade",
+      "Sec-WebSocket-Key"     => "dGhlIHNhbXBsZSBub25jZQ==",
+      "Sec-WebSocket-Version" => "13",
     }
     request = HTTP::Request.new("GET", "/1234", headers)
     io_with_context = create_ws_request_and_return_io(handler, request)
-    io_with_context.to_s.should eq("HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-Websocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=\r\n\r\n")
+    io_with_context.to_s.should eq("HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=\r\n\r\n")
   end
 
   it "matches correct verb" do
diff --git a/src/kemal.cr b/src/kemal.cr
index 13880eae..32300221 100644
--- a/src/kemal.cr
+++ b/src/kemal.cr
@@ -50,7 +50,7 @@ module Kemal
       # This route serves the built-in images for not_found and exceptions.
       get "/__kemal__/404.png" do |env|
         file_path = File.expand_path("lib/kemal/images/404.png", Dir.current)
-        
+
         if File.exists? file_path
           send_file env, file_path
         else
@@ -59,7 +59,7 @@ module Kemal
       end
     end
 
-    config.server ||= HTTP::Server.new(config.host_binding, config.port, config.handlers)
+    server = config.server ||= HTTP::Server.new(config.handlers)
 
     {% if !flag?(:without_openssl) %}
       config.server.not_nil!.tls = config.ssl
@@ -68,13 +68,13 @@ module Kemal
     config.running = true
 
     yield config
-    config.server.not_nil!.listen if config.env != "test" && config.server
+    server.listen(config.host_binding, config.port) if config.env != "test"
   end
 
   def self.stop
     if config.running
-      if config.server
-        config.server.not_nil!.close
+      if server = config.server
+        server.close unless server.closed?
         config.running = false
       else
         raise "Kemal.config.server is not set. Please use Kemal.run to set the server."