diff --git a/client_server_test.go b/client_server_test.go
index 6095c09e..2c848a4b 100644
--- a/client_server_test.go
+++ b/client_server_test.go
@@ -142,6 +142,7 @@ func sendRecv(t *testing.T, ws *Conn) {
 }
 
 func TestProxyDial(t *testing.T) {
+	t.Parallel()
 
 	s := newServer(t)
 	defer s.Close()
@@ -180,6 +181,7 @@ func TestProxyDial(t *testing.T) {
 }
 
 func TestProxyAuthorizationDial(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -220,6 +222,7 @@ func TestProxyAuthorizationDial(t *testing.T) {
 }
 
 func TestDial(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -232,6 +235,7 @@ func TestDial(t *testing.T) {
 }
 
 func TestDialCookieJar(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -294,6 +298,7 @@ func rootCAs(t *testing.T, s *httptest.Server) *x509.CertPool {
 }
 
 func TestDialTLS(t *testing.T) {
+	t.Parallel()
 	s := newTLSServer(t)
 	defer s.Close()
 
@@ -308,6 +313,7 @@ func TestDialTLS(t *testing.T) {
 }
 
 func TestDialTimeout(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -364,6 +370,7 @@ func (c *requireDeadlineNetConn) LocalAddr() net.Addr  { return c.c.LocalAddr()
 func (c *requireDeadlineNetConn) RemoteAddr() net.Addr { return c.c.RemoteAddr() }
 
 func TestHandshakeTimeout(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -380,6 +387,7 @@ func TestHandshakeTimeout(t *testing.T) {
 }
 
 func TestHandshakeTimeoutInContext(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -401,6 +409,7 @@ func TestHandshakeTimeoutInContext(t *testing.T) {
 }
 
 func TestDialBadScheme(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -412,6 +421,7 @@ func TestDialBadScheme(t *testing.T) {
 }
 
 func TestDialBadOrigin(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -429,6 +439,7 @@ func TestDialBadOrigin(t *testing.T) {
 }
 
 func TestDialBadHeader(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -448,6 +459,7 @@ func TestDialBadHeader(t *testing.T) {
 }
 
 func TestBadMethod(t *testing.T) {
+	t.Parallel()
 	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		ws, err := cstUpgrader.Upgrade(w, r, nil)
 		if err == nil {
@@ -476,6 +488,7 @@ func TestBadMethod(t *testing.T) {
 }
 
 func TestDialExtraTokensInRespHeaders(t *testing.T) {
+	t.Parallel()
 	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		challengeKey := r.Header.Get("Sec-Websocket-Key")
 		w.Header().Set("Upgrade", "foo, websocket")
@@ -493,6 +506,7 @@ func TestDialExtraTokensInRespHeaders(t *testing.T) {
 }
 
 func TestHandshake(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -519,6 +533,7 @@ func TestHandshake(t *testing.T) {
 }
 
 func TestRespOnBadHandshake(t *testing.T) {
+	t.Parallel()
 	const expectedStatus = http.StatusGone
 	const expectedBody = "This is the response body."
 
@@ -564,6 +579,7 @@ func (w testLogWriter) Write(p []byte) (int, error) {
 
 // TestHost tests handling of host names and confirms that it matches net/http.
 func TestHost(t *testing.T) {
+	t.Parallel()
 
 	upgrader := Upgrader{}
 	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -745,6 +761,7 @@ func TestHost(t *testing.T) {
 }
 
 func TestDialCompression(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -759,6 +776,7 @@ func TestDialCompression(t *testing.T) {
 }
 
 func TestSocksProxyDial(t *testing.T) {
+	t.Parallel()
 	s := newServer(t)
 	defer s.Close()
 
@@ -846,6 +864,7 @@ func TestSocksProxyDial(t *testing.T) {
 }
 
 func TestTracingDialWithContext(t *testing.T) {
+	t.Parallel()
 
 	var headersWrote, requestWrote, getConn, gotConn, connectDone, gotFirstResponseByte bool
 	trace := &httptrace.ClientTrace{
@@ -905,6 +924,7 @@ func TestTracingDialWithContext(t *testing.T) {
 }
 
 func TestEmptyTracingDialWithContext(t *testing.T) {
+	t.Parallel()
 
 	trace := &httptrace.ClientTrace{}
 	ctx := httptrace.WithClientTrace(context.Background(), trace)
@@ -926,6 +946,7 @@ func TestEmptyTracingDialWithContext(t *testing.T) {
 
 // TestNetDialConnect tests selection of dial method between NetDial, NetDialContext, NetDialTLS or NetDialTLSContext
 func TestNetDialConnect(t *testing.T) {
+	t.Parallel()
 
 	upgrader := Upgrader{}
 	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -1101,6 +1122,7 @@ func TestNetDialConnect(t *testing.T) {
 	}
 }
 func TestNextProtos(t *testing.T) {
+	t.Parallel()
 	ts := httptest.NewUnstartedServer(
 		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}),
 	)
diff --git a/client_test.go b/client_test.go
index 5aa27b37..982b5466 100644
--- a/client_test.go
+++ b/client_test.go
@@ -20,6 +20,7 @@ var hostPortNoPortTests = []struct {
 }
 
 func TestHostPortNoPort(t *testing.T) {
+	t.Parallel()
 	for _, tt := range hostPortNoPortTests {
 		hostPort, hostNoPort := hostPortNoPort(tt.u)
 		if hostPort != tt.hostPort {
diff --git a/compression_test.go b/compression_test.go
index 80cbc4eb..410fb984 100644
--- a/compression_test.go
+++ b/compression_test.go
@@ -12,6 +12,7 @@ type nopCloser struct{ io.Writer }
 func (nopCloser) Close() error { return nil }
 
 func TestTruncWriter(t *testing.T) {
+	t.Parallel()
 	const data = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijlkmnopqrstuvwxyz987654321"
 	for n := 1; n <= 10; n++ {
 		var b bytes.Buffer
@@ -71,6 +72,7 @@ func BenchmarkWriteWithCompression(b *testing.B) {
 }
 
 func TestValidCompressionLevel(t *testing.T) {
+	t.Parallel()
 	c := newTestConn(nil, nil, false)
 	for _, level := range []int{minCompressionLevel - 1, maxCompressionLevel + 1} {
 		if err := c.SetCompressionLevel(level); err == nil {
diff --git a/conn_test.go b/conn_test.go
index 5b27f2f4..fe95b552 100644
--- a/conn_test.go
+++ b/conn_test.go
@@ -54,6 +54,7 @@ func newTestConn(r io.Reader, w io.Writer, isServer bool) *Conn {
 }
 
 func TestFraming(t *testing.T) {
+	t.Parallel()
 	frameSizes := []int{
 		0, 1, 2, 124, 125, 126, 127, 128, 129, 65534, 65535,
 		// 65536, 65537
@@ -148,6 +149,7 @@ func TestFraming(t *testing.T) {
 }
 
 func TestControl(t *testing.T) {
+	t.Parallel()
 	const message = "this is a ping/pong messsage"
 	for _, isServer := range []bool{true, false} {
 		for _, isWriteControl := range []bool{true, false} {
@@ -204,6 +206,7 @@ func (p *simpleBufferPool) Put(v interface{}) {
 }
 
 func TestWriteBufferPool(t *testing.T) {
+	t.Parallel()
 	const message = "Now is the time for all good people to come to the aid of the party."
 
 	var buf bytes.Buffer
@@ -282,6 +285,7 @@ func TestWriteBufferPool(t *testing.T) {
 
 // TestWriteBufferPoolSync ensures that *sync.Pool works as a buffer pool.
 func TestWriteBufferPoolSync(t *testing.T) {
+	t.Parallel()
 	var buf bytes.Buffer
 	var pool sync.Pool
 	wc := newConn(fakeNetConn{Writer: &buf}, true, 1024, 1024, &pool, nil, nil)
@@ -310,6 +314,7 @@ func (ew errorWriter) Write(p []byte) (int, error) { return 0, errors.New("error
 // TestWriteBufferPoolError ensures that buffer is returned to pool after error
 // on write.
 func TestWriteBufferPoolError(t *testing.T) {
+	t.Parallel()
 
 	// Part 1: Test NextWriter/Write/Close
 
@@ -353,6 +358,7 @@ func TestWriteBufferPoolError(t *testing.T) {
 }
 
 func TestCloseFrameBeforeFinalMessageFrame(t *testing.T) {
+	t.Parallel()
 	const bufSize = 512
 
 	expectedErr := &CloseError{Code: CloseNormalClosure, Text: "hello"}
@@ -385,6 +391,7 @@ func TestCloseFrameBeforeFinalMessageFrame(t *testing.T) {
 }
 
 func TestEOFWithinFrame(t *testing.T) {
+	t.Parallel()
 	const bufSize = 64
 
 	for n := 0; ; n++ {
@@ -422,6 +429,7 @@ func TestEOFWithinFrame(t *testing.T) {
 }
 
 func TestEOFBeforeFinalFrame(t *testing.T) {
+	t.Parallel()
 	const bufSize = 512
 
 	var b1, b2 bytes.Buffer
@@ -448,6 +456,7 @@ func TestEOFBeforeFinalFrame(t *testing.T) {
 }
 
 func TestWriteAfterMessageWriterClose(t *testing.T) {
+	t.Parallel()
 	wc := newTestConn(nil, &bytes.Buffer{}, false)
 	w, _ := wc.NextWriter(BinaryMessage)
 	if _, err := io.WriteString(w, "hello"); err != nil {
@@ -478,6 +487,7 @@ func TestWriteAfterMessageWriterClose(t *testing.T) {
 }
 
 func TestWriteHandlerDoesNotReturnErrCloseSent(t *testing.T) {
+	t.Parallel()
 	var b1, b2 bytes.Buffer
 
 	client := newTestConn(&b2, &b1, false)
@@ -498,6 +508,7 @@ func TestWriteHandlerDoesNotReturnErrCloseSent(t *testing.T) {
 }
 
 func TestReadLimit(t *testing.T) {
+	t.Parallel()
 	t.Run("Test ReadLimit is enforced", func(t *testing.T) {
 		const readLimit = 512
 		message := make([]byte, readLimit+1)
@@ -596,6 +607,7 @@ func TestReadLimit(t *testing.T) {
 }
 
 func TestAddrs(t *testing.T) {
+	t.Parallel()
 	c := newTestConn(nil, nil, true)
 	if c.LocalAddr() != localAddr {
 		t.Errorf("LocalAddr = %v, want %v", c.LocalAddr(), localAddr)
@@ -606,6 +618,7 @@ func TestAddrs(t *testing.T) {
 }
 
 func TestDeprecatedUnderlyingConn(t *testing.T) {
+	t.Parallel()
 	var b1, b2 bytes.Buffer
 	fc := fakeNetConn{Reader: &b1, Writer: &b2}
 	c := newConn(fc, true, 1024, 1024, nil, nil, nil)
@@ -616,6 +629,7 @@ func TestDeprecatedUnderlyingConn(t *testing.T) {
 }
 
 func TestNetConn(t *testing.T) {
+	t.Parallel()
 	var b1, b2 bytes.Buffer
 	fc := fakeNetConn{Reader: &b1, Writer: &b2}
 	c := newConn(fc, true, 1024, 1024, nil, nil, nil)
@@ -626,6 +640,7 @@ func TestNetConn(t *testing.T) {
 }
 
 func TestBufioReadBytes(t *testing.T) {
+	t.Parallel()
 	// Test calling bufio.ReadBytes for value longer than read buffer size.
 
 	m := make([]byte, 512)
@@ -668,6 +683,7 @@ var closeErrorTests = []struct {
 }
 
 func TestCloseError(t *testing.T) {
+	t.Parallel()
 	for _, tt := range closeErrorTests {
 		ok := IsCloseError(tt.err, tt.codes...)
 		if ok != tt.ok {
@@ -688,6 +704,7 @@ var unexpectedCloseErrorTests = []struct {
 }
 
 func TestUnexpectedCloseErrors(t *testing.T) {
+	t.Parallel()
 	for _, tt := range unexpectedCloseErrorTests {
 		ok := IsUnexpectedCloseError(tt.err, tt.codes...)
 		if ok != tt.ok {
@@ -709,6 +726,7 @@ func (w blockingWriter) Write(p []byte) (int, error) {
 }
 
 func TestConcurrentWritePanic(t *testing.T) {
+	t.Parallel()
 	w := blockingWriter{make(chan struct{}), make(chan struct{})}
 	c := newTestConn(nil, w, false)
 	go func() {
@@ -740,6 +758,7 @@ func (r failingReader) Read(p []byte) (int, error) {
 }
 
 func TestFailedConnectionReadPanic(t *testing.T) {
+	t.Parallel()
 	c := newTestConn(failingReader{}, nil, false)
 
 	defer func() {
diff --git a/example_test.go b/example_test.go
index cd1883b8..cb3a5eb0 100644
--- a/example_test.go
+++ b/example_test.go
@@ -42,4 +42,4 @@ func processMessage(mt int, p []byte) {}
 
 // TestX prevents godoc from showing this entire file in the example. Remove
 // this function when a second example is added.
-func TestX(t *testing.T) {}
+func TestX(t *testing.T) { t.Parallel() }
diff --git a/join_test.go b/join_test.go
index f06601da..0b3592e6 100644
--- a/join_test.go
+++ b/join_test.go
@@ -12,6 +12,7 @@ import (
 )
 
 func TestJoinMessages(t *testing.T) {
+	t.Parallel()
 	messages := []string{"a", "bc", "def", "ghij", "klmno", "0", "12", "345", "6789"}
 	for _, readChunk := range []int{1, 2, 3, 4, 5, 6, 7} {
 		for _, term := range []string{"", ","} {
diff --git a/json_test.go b/json_test.go
index e4c4bdfe..3e954352 100644
--- a/json_test.go
+++ b/json_test.go
@@ -13,6 +13,7 @@ import (
 )
 
 func TestJSON(t *testing.T) {
+	t.Parallel()
 	var buf bytes.Buffer
 	wc := newTestConn(nil, &buf, true)
 	rc := newTestConn(&buf, nil, false)
@@ -38,6 +39,7 @@ func TestJSON(t *testing.T) {
 }
 
 func TestPartialJSONRead(t *testing.T) {
+	t.Parallel()
 	var buf0, buf1 bytes.Buffer
 	wc := newTestConn(nil, &buf0, true)
 	rc := newTestConn(&buf0, &buf1, false)
@@ -91,6 +93,7 @@ func TestPartialJSONRead(t *testing.T) {
 }
 
 func TestDeprecatedJSON(t *testing.T) {
+	t.Parallel()
 	var buf bytes.Buffer
 	wc := newTestConn(nil, &buf, true)
 	rc := newTestConn(&buf, nil, false)
diff --git a/mask_test.go b/mask_test.go
index 6389f436..718a6b4e 100644
--- a/mask_test.go
+++ b/mask_test.go
@@ -29,6 +29,7 @@ func notzero(b []byte) int {
 }
 
 func TestMaskBytes(t *testing.T) {
+	t.Parallel()
 	key := [4]byte{1, 2, 3, 4}
 	for size := 1; size <= 1024; size++ {
 		for align := 0; align < wordSize; align++ {
diff --git a/server_test.go b/server_test.go
index 0c341ac7..b0dc625f 100644
--- a/server_test.go
+++ b/server_test.go
@@ -27,6 +27,7 @@ var subprotocolTests = []struct {
 }
 
 func TestSubprotocols(t *testing.T) {
+	t.Parallel()
 	for _, st := range subprotocolTests {
 		r := http.Request{Header: http.Header{"Sec-Websocket-Protocol": {st.h}}}
 		protocols := Subprotocols(&r)
@@ -46,6 +47,7 @@ var isWebSocketUpgradeTests = []struct {
 }
 
 func TestIsWebSocketUpgrade(t *testing.T) {
+	t.Parallel()
 	for _, tt := range isWebSocketUpgradeTests {
 		ok := IsWebSocketUpgrade(&http.Request{Header: tt.h})
 		if tt.ok != ok {
@@ -55,6 +57,7 @@ func TestIsWebSocketUpgrade(t *testing.T) {
 }
 
 func TestSubProtocolSelection(t *testing.T) {
+	t.Parallel()
 	upgrader := Upgrader{
 		Subprotocols: []string{"foo", "bar", "baz"},
 	}
@@ -94,6 +97,7 @@ var checkSameOriginTests = []struct {
 }
 
 func TestCheckSameOrigin(t *testing.T) {
+	t.Parallel()
 	for _, tt := range checkSameOriginTests {
 		ok := checkSameOrigin(tt.r)
 		if tt.ok != ok {
@@ -120,6 +124,7 @@ var bufioReuseTests = []struct {
 }
 
 func TestBufioReuse(t *testing.T) {
+	t.Parallel()
 	for i, tt := range bufioReuseTests {
 		br := bufio.NewReaderSize(strings.NewReader(""), tt.n)
 		bw := bufio.NewWriterSize(&bytes.Buffer{}, tt.n)
diff --git a/util_test.go b/util_test.go
index f14d69a1..70621d4c 100644
--- a/util_test.go
+++ b/util_test.go
@@ -21,6 +21,7 @@ var equalASCIIFoldTests = []struct {
 }
 
 func TestEqualASCIIFold(t *testing.T) {
+	t.Parallel()
 	for _, tt := range equalASCIIFoldTests {
 		eq := equalASCIIFold(tt.s, tt.t)
 		if eq != tt.eq {
@@ -44,6 +45,7 @@ var tokenListContainsValueTests = []struct {
 }
 
 func TestTokenListContainsValue(t *testing.T) {
+	t.Parallel()
 	for _, tt := range tokenListContainsValueTests {
 		h := http.Header{"Upgrade": {tt.value}}
 		ok := tokenListContainsValue(h, "Upgrade", "websocket")
@@ -64,6 +66,7 @@ var isValidChallengeKeyTests = []struct {
 }
 
 func TestIsValidChallengeKey(t *testing.T) {
+	t.Parallel()
 	for _, tt := range isValidChallengeKeyTests {
 		ok := isValidChallengeKey(tt.key)
 		if ok != tt.ok {
@@ -105,6 +108,7 @@ var parseExtensionTests = []struct {
 }
 
 func TestParseExtensions(t *testing.T) {
+	t.Parallel()
 	for _, tt := range parseExtensionTests {
 		h := http.Header{http.CanonicalHeaderKey("Sec-WebSocket-Extensions"): {tt.value}}
 		extensions := parseExtensions(h)