diff --git a/rpc/client_test.go b/rpc/client_test.go
index b7607adfce..48467662c9 100644
--- a/rpc/client_test.go
+++ b/rpc/client_test.go
@@ -38,6 +38,8 @@ import (
 )
 
 func TestClientRequest(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	client := DialInProc(server)
@@ -53,6 +55,8 @@ func TestClientRequest(t *testing.T) {
 }
 
 func TestClientResponseType(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	client := DialInProc(server)
@@ -71,6 +75,8 @@ func TestClientResponseType(t *testing.T) {
 
 // This test checks calling a method that returns 'null'.
 func TestClientNullResponse(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 
@@ -91,6 +97,8 @@ func TestClientNullResponse(t *testing.T) {
 
 // This test checks that server-returned errors with code and data come out of Client.Call.
 func TestClientErrorData(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	client := DialInProc(server)
@@ -121,6 +129,8 @@ func TestClientErrorData(t *testing.T) {
 }
 
 func TestClientBatchRequest(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	client := DialInProc(server)
@@ -172,6 +182,8 @@ func TestClientBatchRequest(t *testing.T) {
 // This checks that, for HTTP connections, the length of batch responses is validated to
 // match the request exactly.
 func TestClientBatchRequest_len(t *testing.T) {
+	t.Parallel()
+
 	b, err := json.Marshal([]jsonrpcMessage{
 		{Version: "2.0", ID: json.RawMessage("1"), Result: json.RawMessage(`"0x1"`)},
 		{Version: "2.0", ID: json.RawMessage("2"), Result: json.RawMessage(`"0x2"`)},
@@ -188,6 +200,8 @@ func TestClientBatchRequest_len(t *testing.T) {
 	t.Cleanup(s.Close)
 
 	t.Run("too-few", func(t *testing.T) {
+		t.Parallel()
+
 		client, err := Dial(s.URL)
 		if err != nil {
 			t.Fatal("failed to dial test server:", err)
@@ -218,6 +232,8 @@ func TestClientBatchRequest_len(t *testing.T) {
 	})
 
 	t.Run("too-many", func(t *testing.T) {
+		t.Parallel()
+
 		client, err := Dial(s.URL)
 		if err != nil {
 			t.Fatal("failed to dial test server:", err)
@@ -249,6 +265,8 @@ func TestClientBatchRequest_len(t *testing.T) {
 // This checks that the client can handle the case where the server doesn't
 // respond to all requests in a batch.
 func TestClientBatchRequestLimit(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	server.SetBatchLimits(2, 100000)
@@ -285,6 +303,8 @@ func TestClientBatchRequestLimit(t *testing.T) {
 }
 
 func TestClientNotify(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	client := DialInProc(server)
@@ -392,6 +412,8 @@ func testClientCancel(transport string, t *testing.T) {
 }
 
 func TestClientSubscribeInvalidArg(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	client := DialInProc(server)
@@ -422,6 +444,8 @@ func TestClientSubscribeInvalidArg(t *testing.T) {
 }
 
 func TestClientSubscribe(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	client := DialInProc(server)
@@ -454,6 +478,8 @@ func TestClientSubscribe(t *testing.T) {
 
 // In this test, the connection drops while Subscribe is waiting for a response.
 func TestClientSubscribeClose(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	service := &notificationTestService{
 		gotHangSubscriptionReq:  make(chan struct{}),
@@ -498,6 +524,8 @@ func TestClientSubscribeClose(t *testing.T) {
 // This test reproduces https://github.com/ethereum/go-ethereum/issues/17837 where the
 // client hangs during shutdown when Unsubscribe races with Client.Close.
 func TestClientCloseUnsubscribeRace(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 
@@ -540,6 +568,8 @@ func (b *unsubscribeBlocker) readBatch() ([]*jsonrpcMessage, bool, error) {
 // not respond.
 // It reproducers the issue https://github.com/ethereum/go-ethereum/issues/30156
 func TestUnsubscribeTimeout(t *testing.T) {
+	t.Parallel()
+
 	srv := NewServer()
 	srv.RegisterName("nftest", new(notificationTestService))
 
@@ -674,6 +704,8 @@ func TestClientSubscriptionChannelClose(t *testing.T) {
 // This test checks that Client doesn't lock up when a single subscriber
 // doesn't read subscription events.
 func TestClientNotificationStorm(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 
@@ -726,6 +758,8 @@ func TestClientNotificationStorm(t *testing.T) {
 }
 
 func TestClientSetHeader(t *testing.T) {
+	t.Parallel()
+
 	var gotHeader bool
 	srv := newTestServer()
 	httpsrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -762,6 +796,8 @@ func TestClientSetHeader(t *testing.T) {
 }
 
 func TestClientHTTP(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 
@@ -805,6 +841,8 @@ func TestClientHTTP(t *testing.T) {
 }
 
 func TestClientReconnect(t *testing.T) {
+	t.Parallel()
+
 	startServer := func(addr string) (*Server, net.Listener) {
 		srv := newTestServer()
 		l, err := net.Listen("tcp", addr)
diff --git a/rpc/http_test.go b/rpc/http_test.go
index ad86ca15ae..6c268b6292 100644
--- a/rpc/http_test.go
+++ b/rpc/http_test.go
@@ -58,24 +58,34 @@ func confirmRequestValidationCode(t *testing.T, method, contentType, body string
 }
 
 func TestHTTPErrorResponseWithDelete(t *testing.T) {
+	t.Parallel()
+
 	confirmRequestValidationCode(t, http.MethodDelete, contentType, "", http.StatusMethodNotAllowed)
 }
 
 func TestHTTPErrorResponseWithPut(t *testing.T) {
+	t.Parallel()
+
 	confirmRequestValidationCode(t, http.MethodPut, contentType, "", http.StatusMethodNotAllowed)
 }
 
 func TestHTTPErrorResponseWithMaxContentLength(t *testing.T) {
+	t.Parallel()
+
 	body := make([]rune, defaultBodyLimit+1)
 	confirmRequestValidationCode(t,
 		http.MethodPost, contentType, string(body), http.StatusRequestEntityTooLarge)
 }
 
 func TestHTTPErrorResponseWithEmptyContentType(t *testing.T) {
+	t.Parallel()
+
 	confirmRequestValidationCode(t, http.MethodPost, "", "", http.StatusUnsupportedMediaType)
 }
 
 func TestHTTPErrorResponseWithValidRequest(t *testing.T) {
+	t.Parallel()
+
 	confirmRequestValidationCode(t, http.MethodPost, contentType, "", 0)
 }
 
@@ -101,11 +111,15 @@ func confirmHTTPRequestYieldsStatusCode(t *testing.T, method, contentType, body
 }
 
 func TestHTTPResponseWithEmptyGet(t *testing.T) {
+	t.Parallel()
+
 	confirmHTTPRequestYieldsStatusCode(t, http.MethodGet, "", "", http.StatusOK)
 }
 
 // This checks that maxRequestContentLength is not applied to the response of a request.
 func TestHTTPRespBodyUnlimited(t *testing.T) {
+	t.Parallel()
+
 	const respLength = defaultBodyLimit * 3
 
 	s := NewServer()
@@ -132,6 +146,8 @@ func TestHTTPRespBodyUnlimited(t *testing.T) {
 // Tests that an HTTP error results in an HTTPError instance
 // being returned with the expected attributes.
 func TestHTTPErrorResponse(t *testing.T) {
+	t.Parallel()
+
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "error has occurred!", http.StatusTeapot)
 	}))
@@ -169,6 +185,8 @@ func TestHTTPErrorResponse(t *testing.T) {
 }
 
 func TestHTTPPeerInfo(t *testing.T) {
+	t.Parallel()
+
 	s := newTestServer()
 	defer s.Stop()
 	ts := httptest.NewServer(s)
@@ -205,6 +223,8 @@ func TestHTTPPeerInfo(t *testing.T) {
 }
 
 func TestNewContextWithHeaders(t *testing.T) {
+	t.Parallel()
+
 	expectedHeaders := 0
 	server := httptest.NewServer(http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
 		for i := 0; i < expectedHeaders; i++ {
diff --git a/rpc/server_test.go b/rpc/server_test.go
index 9d1c7fb5f0..9ee545d81a 100644
--- a/rpc/server_test.go
+++ b/rpc/server_test.go
@@ -29,6 +29,8 @@ import (
 )
 
 func TestServerRegisterName(t *testing.T) {
+	t.Parallel()
+
 	server := NewServer()
 	service := new(testService)
 
@@ -53,6 +55,8 @@ func TestServerRegisterName(t *testing.T) {
 }
 
 func TestServer(t *testing.T) {
+	t.Parallel()
+
 	files, err := os.ReadDir("testdata")
 	if err != nil {
 		t.Fatal("where'd my testdata go?")
@@ -64,6 +68,8 @@ func TestServer(t *testing.T) {
 		path := filepath.Join("testdata", f.Name())
 		name := strings.TrimSuffix(f.Name(), filepath.Ext(f.Name()))
 		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
 			runTestScript(t, path)
 		})
 	}
@@ -116,6 +122,8 @@ func runTestScript(t *testing.T, file string) {
 // This test checks that responses are delivered for very short-lived connections that
 // only carry a single request.
 func TestServerShortLivedConn(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 
@@ -156,6 +164,8 @@ func TestServerShortLivedConn(t *testing.T) {
 }
 
 func TestServerBatchResponseSizeLimit(t *testing.T) {
+	t.Parallel()
+
 	server := newTestServer()
 	defer server.Stop()
 	server.SetBatchLimits(100, 60)
diff --git a/rpc/subscription_test.go b/rpc/subscription_test.go
index ab40ab169f..e52f390adb 100644
--- a/rpc/subscription_test.go
+++ b/rpc/subscription_test.go
@@ -33,6 +33,8 @@ import (
 )
 
 func TestNewID(t *testing.T) {
+	t.Parallel()
+
 	hexchars := "0123456789ABCDEFabcdef"
 	for i := 0; i < 100; i++ {
 		id := string(NewID())
@@ -54,6 +56,8 @@ func TestNewID(t *testing.T) {
 }
 
 func TestSubscriptions(t *testing.T) {
+	t.Parallel()
+
 	var (
 		namespaces        = []string{"eth", "bzz"}
 		service           = &notificationTestService{}
@@ -132,6 +136,8 @@ func TestSubscriptions(t *testing.T) {
 
 // This test checks that unsubscribing works.
 func TestServerUnsubscribe(t *testing.T) {
+	t.Parallel()
+
 	p1, p2 := net.Pipe()
 	defer p2.Close()
 
@@ -260,6 +266,8 @@ func BenchmarkNotify(b *testing.B) {
 }
 
 func TestNotify(t *testing.T) {
+	t.Parallel()
+
 	out := new(bytes.Buffer)
 	id := ID("test")
 	notifier := &Notifier{
diff --git a/rpc/types_test.go b/rpc/types_test.go
index 2fa74f9899..a1323b6f63 100644
--- a/rpc/types_test.go
+++ b/rpc/types_test.go
@@ -26,6 +26,8 @@ import (
 )
 
 func TestBlockNumberJSONUnmarshal(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		input    string
 		mustFail bool
@@ -70,6 +72,8 @@ func TestBlockNumberJSONUnmarshal(t *testing.T) {
 }
 
 func TestBlockNumberOrHash_UnmarshalJSON(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		input    string
 		mustFail bool
@@ -131,6 +135,8 @@ func TestBlockNumberOrHash_UnmarshalJSON(t *testing.T) {
 }
 
 func TestBlockNumberOrHash_WithNumber_MarshalAndUnmarshal(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name   string
 		number int64
@@ -145,6 +151,8 @@ func TestBlockNumberOrHash_WithNumber_MarshalAndUnmarshal(t *testing.T) {
 	for _, test := range tests {
 		test := test
 		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
 			bnh := BlockNumberOrHashWithNumber(BlockNumber(test.number))
 			marshalled, err := json.Marshal(bnh)
 			if err != nil {
@@ -163,6 +171,8 @@ func TestBlockNumberOrHash_WithNumber_MarshalAndUnmarshal(t *testing.T) {
 }
 
 func TestBlockNumberOrHash_StringAndUnmarshal(t *testing.T) {
+	t.Parallel()
+
 	tests := []BlockNumberOrHash{
 		BlockNumberOrHashWithNumber(math.MaxInt64),
 		BlockNumberOrHashWithNumber(PendingBlockNumber),
diff --git a/rpc/websocket_test.go b/rpc/websocket_test.go
index c6ea325d29..10a998b351 100644
--- a/rpc/websocket_test.go
+++ b/rpc/websocket_test.go
@@ -174,6 +174,8 @@ func TestWebsocketLargeRead(t *testing.T) {
 }
 
 func TestWebsocketPeerInfo(t *testing.T) {
+	t.Parallel()
+
 	var (
 		s     = newTestServer()
 		ts    = httptest.NewServer(s.WebsocketHandler([]string{"origin.example.com"}))
@@ -259,6 +261,8 @@ func TestClientWebsocketPing(t *testing.T) {
 
 // This checks that the websocket transport can deal with large messages.
 func TestClientWebsocketLargeMessage(t *testing.T) {
+	t.Parallel()
+
 	var (
 		srv     = NewServer()
 		httpsrv = httptest.NewServer(srv.WebsocketHandler(nil))