diff --git a/lib/websocket/driver/hybi.rb b/lib/websocket/driver/hybi.rb
index 3db3ee1..d906a91 100644
--- a/lib/websocket/driver/hybi.rb
+++ b/lib/websocket/driver/hybi.rb
@@ -181,17 +181,16 @@ module WebSocket
         reason ||= ''
         code   ||= ERRORS[:normal_closure]
 
-        case @ready_state
-          when 0 then
-            @ready_state = 3
-            emit(:close, CloseEvent.new(code, reason))
-            true
-          when 1 then
-            frame(reason, :close, code)
-            @ready_state = 2
-            true
-          else
-            false
+        if @ready_state <= 0
+          @ready_state = 3
+          emit(:close, CloseEvent.new(code, reason))
+          true
+        elsif @ready_state == 1
+          frame(reason, :close, code)
+          @ready_state = 2
+          true
+        else
+          false
         end
       end
 
diff --git a/spec/websocket/driver/client_spec.rb b/spec/websocket/driver/client_spec.rb
index dba7d21..27fb8c6 100644
--- a/spec/websocket/driver/client_spec.rb
+++ b/spec/websocket/driver/client_spec.rb
@@ -54,6 +54,14 @@ describe WebSocket::Driver::Client do
       expect(driver.state).to eq nil
     end
 
+    describe :close do
+      it "changes the state to closed" do
+        driver.close
+        expect(driver.state).to eq :closed
+        expect(@close).to eq [1000, ""]
+      end
+    end
+
     describe :start do
       it "writes the handshake request to the socket" do
         expect(socket).to receive(:write).with(