diff --git a/internal/breaker/os_signal_test.go b/internal/breaker/os_signal_test.go
index 26de81f..fc2fc29 100644
--- a/internal/breaker/os_signal_test.go
+++ b/internal/breaker/os_signal_test.go
@@ -12,8 +12,6 @@ import (
 )
 
 func TestNewOSSignals(t *testing.T) {
-	t.Parallel()
-
 	oss := breaker.NewOSSignals(context.Background())
 
 	gotSignal := make(chan os.Signal, 1)
@@ -35,8 +33,6 @@ func TestNewOSSignals(t *testing.T) {
 }
 
 func TestNewOSSignalCtxCancel(t *testing.T) {
-	t.Parallel()
-
 	ctx, cancel := context.WithCancel(context.Background())
 
 	oss := breaker.NewOSSignals(ctx)
diff --git a/internal/checkers/health_test.go b/internal/checkers/health_test.go
index 2218af2..85bdb77 100644
--- a/internal/checkers/health_test.go
+++ b/internal/checkers/health_test.go
@@ -16,8 +16,6 @@ type httpClientFunc func(*http.Request) (*http.Response, error)
 func (f httpClientFunc) Do(req *http.Request) (*http.Response, error) { return f(req) }
 
 func TestHealthChecker_CheckSuccess(t *testing.T) {
-	t.Parallel()
-
 	var httpMock httpClientFunc = func(req *http.Request) (*http.Response, error) {
 		assert.Equal(t, http.MethodGet, req.Method)
 		assert.Equal(t, "http://127.0.0.1:123/healthz", req.URL.String())
@@ -35,8 +33,6 @@ func TestHealthChecker_CheckSuccess(t *testing.T) {
 }
 
 func TestHealthChecker_CheckFail(t *testing.T) {
-	t.Parallel()
-
 	var httpMock httpClientFunc = func(req *http.Request) (*http.Response, error) {
 		return &http.Response{
 			Body:       ioutil.NopCloser(bytes.NewReader([]byte{})),
diff --git a/internal/checkers/live_test.go b/internal/checkers/live_test.go
index 1b622e6..413d89b 100644
--- a/internal/checkers/live_test.go
+++ b/internal/checkers/live_test.go
@@ -8,7 +8,5 @@ import (
 )
 
 func TestLiveChecker_Check(t *testing.T) {
-	t.Parallel()
-
 	assert.NoError(t, checkers.NewLiveChecker().Check())
 }
diff --git a/internal/cli/build/command_test.go b/internal/cli/build/command_test.go
index 9db3223..df9157a 100644
--- a/internal/cli/build/command_test.go
+++ b/internal/cli/build/command_test.go
@@ -3,7 +3,5 @@ package build_test
 import "testing"
 
 func TestNothing(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/cli/healthcheck/command_test.go b/internal/cli/healthcheck/command_test.go
index 0a12053..233aa90 100644
--- a/internal/cli/healthcheck/command_test.go
+++ b/internal/cli/healthcheck/command_test.go
@@ -16,8 +16,6 @@ type fakeChecker struct{ err error }
 func (c *fakeChecker) Check(port uint16) error { return c.err }
 
 func TestProperties(t *testing.T) {
-	t.Parallel()
-
 	cmd := healthcheck.NewCommand(&fakeChecker{err: nil})
 
 	assert.Equal(t, "healthcheck", cmd.Use)
diff --git a/internal/cli/root_test.go b/internal/cli/root_test.go
index 78398f6..e023fc6 100644
--- a/internal/cli/root_test.go
+++ b/internal/cli/root_test.go
@@ -9,8 +9,6 @@ import (
 )
 
 func TestSubcommands(t *testing.T) {
-	t.Parallel()
-
 	cmd := cli.NewCommand("unit test")
 
 	cases := []struct {
@@ -31,8 +29,6 @@ func TestSubcommands(t *testing.T) {
 	for _, tt := range cases {
 		tt := tt
 		t.Run(tt.giveName, func(t *testing.T) {
-			t.Parallel()
-
 			if _, exists := subcommands[tt.giveName]; !exists {
 				assert.Failf(t, "command not found", "command [%s] was not found", tt.giveName)
 			}
@@ -41,8 +37,6 @@ func TestSubcommands(t *testing.T) {
 }
 
 func TestFlags(t *testing.T) {
-	t.Parallel()
-
 	cmd := cli.NewCommand("unit test")
 
 	cases := []struct {
@@ -59,8 +53,6 @@ func TestFlags(t *testing.T) {
 	for _, tt := range cases {
 		tt := tt
 		t.Run(tt.giveName, func(t *testing.T) {
-			t.Parallel()
-
 			flag := cmd.Flag(tt.giveName)
 
 			if flag == nil {
@@ -76,8 +68,6 @@ func TestFlags(t *testing.T) {
 }
 
 func TestExecuting(t *testing.T) {
-	t.Parallel()
-
 	cmd := cli.NewCommand("unit test")
 	cmd.SetArgs([]string{})
 
diff --git a/internal/cli/serve/command_test.go b/internal/cli/serve/command_test.go
index 8b48ee1..2882055 100644
--- a/internal/cli/serve/command_test.go
+++ b/internal/cli/serve/command_test.go
@@ -3,7 +3,5 @@ package serve_test
 import "testing"
 
 func TestNothing(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/cli/version/command_test.go b/internal/cli/version/command_test.go
index 98e95f4..27db5bc 100644
--- a/internal/cli/version/command_test.go
+++ b/internal/cli/version/command_test.go
@@ -10,8 +10,6 @@ import (
 )
 
 func TestProperties(t *testing.T) {
-	t.Parallel()
-
 	cmd := version.NewCommand("")
 
 	assert.Equal(t, "version", cmd.Use)
@@ -20,8 +18,6 @@ func TestProperties(t *testing.T) {
 }
 
 func TestCommandRun(t *testing.T) {
-	t.Parallel()
-
 	cmd := version.NewCommand("1.2.3@foobar")
 	cmd.SetArgs([]string{})
 
diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index 2dda2c7..131b202 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -9,8 +9,6 @@ import (
 )
 
 func TestFromYaml(t *testing.T) {
-	t.Parallel()
-
 	var cases = map[string]struct { //nolint:maligned
 		giveYaml      []byte
 		giveEnv       map[string]string
@@ -111,8 +109,6 @@ pages:
 
 	for name, tt := range cases {
 		t.Run(name, func(t *testing.T) {
-			t.Parallel()
-
 			if tt.giveEnv != nil {
 				for key, value := range tt.giveEnv {
 					assert.NoError(t, os.Setenv(key, value))
diff --git a/internal/env/env_test.go b/internal/env/env_test.go
index 192b648..a97dd7c 100644
--- a/internal/env/env_test.go
+++ b/internal/env/env_test.go
@@ -8,8 +8,6 @@ import (
 )
 
 func TestConstants(t *testing.T) {
-	t.Parallel()
-
 	assert.Equal(t, "LISTEN_ADDR", string(ListenAddr))
 	assert.Equal(t, "LISTEN_PORT", string(ListenPort))
 	assert.Equal(t, "TEMPLATE_NAME", string(TemplateName))
diff --git a/internal/http/common/middlewares_test.go b/internal/http/common/middlewares_test.go
index 7b2a699..f65e6b8 100644
--- a/internal/http/common/middlewares_test.go
+++ b/internal/http/common/middlewares_test.go
@@ -3,7 +3,5 @@ package common_test
 import "testing"
 
 func TestNothing2(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/http/core/formats.go b/internal/http/core/formats.go
index c7e2b15..e592c04 100644
--- a/internal/http/core/formats.go
+++ b/internal/http/core/formats.go
@@ -2,6 +2,8 @@ package core
 
 import (
 	"bytes"
+	"sort"
+	"strconv"
 
 	"github.com/valyala/fasthttp"
 )
@@ -17,28 +19,66 @@ const (
 )
 
 func ClientWantFormat(ctx *fasthttp.RequestCtx) ContentType {
-	var (
-		ct = bytes.ToLower(ctx.Request.Header.ContentType())
-		f  = bytes.ToLower(ctx.Request.Header.Peek(FormatHeader)) // for the Ingress support
-	)
+	// parse "Content-Type" header (e.g.: `application/json;charset=UTF-8`)
+	if ct := bytes.ToLower(ctx.Request.Header.ContentType()); len(ct) > 4 { //nolint:gomnd
+		return mimeTypeToContentType(ct)
+	}
 
+	// parse `X-Format` header (aka `Accept`) for the Ingress support
+	// e.g.: `text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8`
+	if h := bytes.ToLower(bytes.TrimSpace(ctx.Request.Header.Peek(FormatHeader))); len(h) > 2 { //nolint:gomnd,nestif
+		type format struct {
+			mimeType []byte
+			weight   float32
+		}
+
+		var formats = make([]format, 0, 8) //nolint:gomnd
+
+		for _, b := range bytes.FieldsFunc(h, func(r rune) bool { return r == ',' }) {
+			if idx := bytes.Index(b, []byte(";q=")); idx > 0 && idx < len(b) {
+				f := format{b[0:idx], 0}
+
+				if len(b) > idx+3 {
+					if weight, err := strconv.ParseFloat(string(b[idx+3:]), 32); err == nil { //nolint:gomnd
+						f.weight = float32(weight)
+					}
+				}
+
+				formats = append(formats, f)
+			} else {
+				formats = append(formats, format{b, 1})
+			}
+		}
+
+		switch l := len(formats); {
+		case l == 0:
+			return UnknownContentType
+
+		case l == 1:
+			return mimeTypeToContentType(formats[0].mimeType)
+
+		default:
+			sort.SliceStable(formats, func(i, j int) bool { return formats[i].weight > formats[j].weight })
+
+			return mimeTypeToContentType(formats[0].mimeType)
+		}
+	}
+
+	return UnknownContentType
+}
+
+func mimeTypeToContentType(mimeType []byte) ContentType {
 	switch {
-	case bytes.Contains(f, []byte("json")),
-		bytes.Contains(ct, []byte("application/json")),
-		bytes.Contains(ct, []byte("text/json")):
+	case bytes.Contains(mimeType, []byte("application/json")), bytes.Contains(mimeType, []byte("text/json")):
 		return JSONContentType
 
-	case bytes.Contains(f, []byte("xml")),
-		bytes.Contains(ct, []byte("application/xml")),
-		bytes.Contains(ct, []byte("text/xml")):
+	case bytes.Contains(mimeType, []byte("application/xml")), bytes.Contains(mimeType, []byte("text/xml")):
 		return XMLContentType
 
-	case bytes.Contains(f, []byte("html")),
-		bytes.Contains(ct, []byte("text/html")):
+	case bytes.Contains(mimeType, []byte("text/html")):
 		return HTMLContentType
 
-	case bytes.Contains(f, []byte("plain")),
-		bytes.Contains(ct, []byte("text/plain")):
+	case bytes.Contains(mimeType, []byte("text/plain")):
 		return PlainTextContentType
 	}
 
diff --git a/internal/http/core/formats_test.go b/internal/http/core/formats_test.go
index f4a28d6..1237b8e 100644
--- a/internal/http/core/formats_test.go
+++ b/internal/http/core/formats_test.go
@@ -9,14 +9,26 @@ import (
 )
 
 func TestClientWantFormat(t *testing.T) {
-	t.Parallel()
-
 	for name, tt := range map[string]struct {
 		giveContentTypeHeader string
 		giveFormatHeader      string
 		giveReqCtx            func() *fasthttp.RequestCtx
 		wantFormat            core.ContentType
 	}{
+		"priority": {
+			giveFormatHeader:      "application/xml",
+			giveContentTypeHeader: "text/plain",
+			wantFormat:            core.PlainTextContentType,
+		},
+		"format respects weight": {
+			giveFormatHeader: "text/html;q=0.5,application/xhtml+xml;q=0.9,application/xml;q=1,*/*;q=0.8",
+			wantFormat:       core.XMLContentType,
+		},
+		"wrong format value": {
+			giveFormatHeader: ";q=foobar,bar/baz;;;;;application/xml",
+			wantFormat:       core.UnknownContentType,
+		},
+
 		"content type - application/json": {
 			giveContentTypeHeader: "application/jsoN; charset=utf-8", wantFormat: core.JSONContentType,
 		},
@@ -24,7 +36,7 @@ func TestClientWantFormat(t *testing.T) {
 			giveContentTypeHeader: "text/Json; charset=utf-8", wantFormat: core.JSONContentType,
 		},
 		"format - json": {
-			giveFormatHeader: "jsOn", wantFormat: core.JSONContentType,
+			giveFormatHeader: "application/jsoN,*/*;q=0.8", wantFormat: core.JSONContentType,
 		},
 
 		"content type - application/xml": {
@@ -34,21 +46,22 @@ func TestClientWantFormat(t *testing.T) {
 			giveContentTypeHeader: "text/Xml; charset=utf-8", wantFormat: core.XMLContentType,
 		},
 		"format - xml": {
-			giveFormatHeader: "xMl", wantFormat: core.XMLContentType,
+			giveFormatHeader: "text/Xml", wantFormat: core.XMLContentType,
 		},
 
 		"content type - text/html": {
 			giveContentTypeHeader: "text/htMl; charset=utf-8", wantFormat: core.HTMLContentType,
 		},
 		"format - html": {
-			giveFormatHeader: "HtmL", wantFormat: core.HTMLContentType,
+			giveFormatHeader: "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
+			wantFormat:       core.HTMLContentType,
 		},
 
 		"content type - text/plain": {
 			giveContentTypeHeader: "text/plaiN; charset=utf-8", wantFormat: core.PlainTextContentType,
 		},
 		"format - plain": {
-			giveFormatHeader: "PLAIN", wantFormat: core.PlainTextContentType,
+			giveFormatHeader: "text/plaiN,text/html,application/xml;q=0.9,,,*/*;q=0.8", wantFormat: core.PlainTextContentType,
 		},
 
 		"unknown on empty": {
@@ -61,8 +74,6 @@ func TestClientWantFormat(t *testing.T) {
 		},
 	} {
 		t.Run(name, func(t *testing.T) {
-			t.Parallel()
-
 			h := &fasthttp.RequestHeader{}
 			h.Set(fasthttp.HeaderContentType, tt.giveContentTypeHeader)
 			h.Set(core.FormatHeader, tt.giveFormatHeader)
@@ -79,8 +90,6 @@ func TestClientWantFormat(t *testing.T) {
 }
 
 func TestSetClientFormat(t *testing.T) {
-	t.Parallel()
-
 	for name, tt := range map[string]struct {
 		giveContentType core.ContentType
 		wantHeaderValue string
@@ -92,8 +101,6 @@ func TestSetClientFormat(t *testing.T) {
 		"plain":            {giveContentType: core.PlainTextContentType, wantHeaderValue: "text/plain; charset=utf-8"},
 	} {
 		t.Run(name, func(t *testing.T) {
-			t.Parallel()
-
 			ctx := &fasthttp.RequestCtx{
 				Response: fasthttp.Response{
 					Header: fasthttp.ResponseHeader{},
diff --git a/internal/http/handlers/errorpage/handler_test.go b/internal/http/handlers/errorpage/handler_test.go
index a262578..5c974ff 100644
--- a/internal/http/handlers/errorpage/handler_test.go
+++ b/internal/http/handlers/errorpage/handler_test.go
@@ -3,7 +3,5 @@ package errorpage_test
 import "testing"
 
 func TestNothing(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/http/handlers/healthz/handler_test.go b/internal/http/handlers/healthz/handler_test.go
index 585e1d2..fbc25f2 100644
--- a/internal/http/handlers/healthz/handler_test.go
+++ b/internal/http/handlers/healthz/handler_test.go
@@ -3,7 +3,5 @@ package healthz_test
 import "testing"
 
 func TestNothing(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/http/handlers/index/handler_test.go b/internal/http/handlers/index/handler_test.go
index 4530471..4543537 100644
--- a/internal/http/handlers/index/handler_test.go
+++ b/internal/http/handlers/index/handler_test.go
@@ -3,7 +3,5 @@ package index_test
 import "testing"
 
 func TestNothing(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/http/handlers/notfound/handler_test.go b/internal/http/handlers/notfound/handler_test.go
index e0b7c0b..3daed4d 100644
--- a/internal/http/handlers/notfound/handler_test.go
+++ b/internal/http/handlers/notfound/handler_test.go
@@ -3,7 +3,5 @@ package notfound_test
 import "testing"
 
 func TestNothing(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/http/handlers/version/handler_test.go b/internal/http/handlers/version/handler_test.go
index 7014943..72c102b 100644
--- a/internal/http/handlers/version/handler_test.go
+++ b/internal/http/handlers/version/handler_test.go
@@ -3,7 +3,5 @@ package version_test
 import "testing"
 
 func TestNothing(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/http/server_test.go b/internal/http/server_test.go
index 5b4081f..66c2992 100644
--- a/internal/http/server_test.go
+++ b/internal/http/server_test.go
@@ -3,7 +3,5 @@ package http
 import "testing"
 
 func TestNothing(t *testing.T) {
-	t.Parallel()
-
 	t.Skip("tests for this package have not been implemented yet")
 }
diff --git a/internal/pick/picker_test.go b/internal/pick/picker_test.go
index abef747..12d7783 100644
--- a/internal/pick/picker_test.go
+++ b/internal/pick/picker_test.go
@@ -8,8 +8,6 @@ import (
 )
 
 func TestPicker_NextIndex_First(t *testing.T) {
-	t.Parallel()
-
 	for i := uint32(0); i < 100; i++ {
 		p := pick.NewPicker(i, pick.First)
 
@@ -20,8 +18,6 @@ func TestPicker_NextIndex_First(t *testing.T) {
 }
 
 func TestPicker_NextIndex_RandomOnce(t *testing.T) {
-	t.Parallel()
-
 	for i := uint8(0); i < 10; i++ {
 		assert.Equal(t, uint32(0), pick.NewPicker(0, pick.RandomOnce).NextIndex())
 	}
@@ -39,8 +35,6 @@ func TestPicker_NextIndex_RandomOnce(t *testing.T) {
 }
 
 func TestPicker_NextIndex_RandomEveryTime(t *testing.T) {
-	t.Parallel()
-
 	for i := uint8(0); i < 10; i++ {
 		assert.Equal(t, uint32(0), pick.NewPicker(0, pick.RandomEveryTime).NextIndex())
 	}
@@ -59,7 +53,5 @@ func TestPicker_NextIndex_RandomEveryTime(t *testing.T) {
 }
 
 func TestPicker_NextIndex_Unsupported(t *testing.T) {
-	t.Parallel()
-
 	assert.Panics(t, func() { pick.NewPicker(1, 255).NextIndex() })
 }
diff --git a/internal/pick/strings_slice_test.go b/internal/pick/strings_slice_test.go
index 4b92ff7..baa2dca 100644
--- a/internal/pick/strings_slice_test.go
+++ b/internal/pick/strings_slice_test.go
@@ -8,11 +8,7 @@ import (
 )
 
 func TestStringsSlice_Pick(t *testing.T) {
-	t.Parallel()
-
 	t.Run("first", func(t *testing.T) {
-		t.Parallel()
-
 		for i := uint8(0); i < 100; i++ {
 			assert.Equal(t, "", pick.NewStringsSlice([]string{}, pick.First).Pick())
 		}
@@ -25,8 +21,6 @@ func TestStringsSlice_Pick(t *testing.T) {
 	})
 
 	t.Run("random once", func(t *testing.T) {
-		t.Parallel()
-
 		for i := uint8(0); i < 100; i++ {
 			assert.Equal(t, "", pick.NewStringsSlice([]string{}, pick.RandomOnce).Pick())
 		}
@@ -42,8 +36,6 @@ func TestStringsSlice_Pick(t *testing.T) {
 	})
 
 	t.Run("random every time", func(t *testing.T) {
-		t.Parallel()
-
 		for i := uint8(0); i < 100; i++ {
 			assert.Equal(t, "", pick.NewStringsSlice([]string{}, pick.RandomEveryTime).Pick())
 		}
diff --git a/internal/tpl/properties_test.go b/internal/tpl/properties_test.go
index 4db033f..d2d1e2a 100644
--- a/internal/tpl/properties_test.go
+++ b/internal/tpl/properties_test.go
@@ -8,8 +8,6 @@ import (
 )
 
 func TestProperties_Replaces(t *testing.T) {
-	t.Parallel()
-
 	props := tpl.Properties{
 		Code:        "foo",
 		Message:     "bar",
diff --git a/internal/tpl/render_test.go b/internal/tpl/render_test.go
index 82b7702..6f4d908 100644
--- a/internal/tpl/render_test.go
+++ b/internal/tpl/render_test.go
@@ -8,8 +8,6 @@ import (
 )
 
 func Test_Render(t *testing.T) {
-	t.Parallel()
-
 	for name, tt := range map[string]struct {
 		giveContent string
 		giveProps   tpl.Properties
@@ -54,8 +52,6 @@ func Test_Render(t *testing.T) {
 		},
 	} {
 		t.Run(name, func(t *testing.T) {
-			t.Parallel()
-
 			content, err := tpl.Render([]byte(tt.giveContent), tt.giveProps)
 
 			if tt.wantError == true {
diff --git a/internal/version/version_test.go b/internal/version/version_test.go
index ade2466..bed3e5b 100644
--- a/internal/version/version_test.go
+++ b/internal/version/version_test.go
@@ -5,8 +5,6 @@ import (
 )
 
 func TestVersion(t *testing.T) {
-	t.Parallel()
-
 	for give, want := range map[string]string{
 		// without changes
 		"vvv":     "vvv",
diff --git a/test/hurl/x_code.hurl b/test/hurl/x_code.hurl
index 4529cb0..a0f0133 100644
--- a/test/hurl/x_code.hurl
+++ b/test/hurl/x_code.hurl
@@ -13,7 +13,7 @@ body contains "Gone"
 # X-Code with X-Format
 GET http://{{ host }}:{{ port }}/
 X-Code: 410
-X-Format: text/json
+X-Format: text/html;q=0.9,application/xhtml+xml;q=0.9,application/json,image/avif,image/webp,*/*;q=0.8
 
 HTTP/* 410