diff --git a/headercase_test.go b/headercase_test.go
new file mode 100644
index 0000000..7fb6e61
--- /dev/null
+++ b/headercase_test.go
@@ -0,0 +1,122 @@
+package rawhttp
+
+import (
+	"bufio"
+	"bytes"
+	"compress/gzip"
+	"io"
+	"net"
+	"strconv"
+	"testing"
+	"time"
+)
+
+func rawSrv(t *testing.T, responses ...string) string {
+	t.Helper()
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = ln.Close() })
+	go func() {
+		i := 0
+		for {
+			c, err := ln.Accept()
+			if err != nil {
+				return
+			}
+			resp := responses[i%len(responses)]
+			i++
+			go func(c net.Conn, resp string) {
+				defer func() { _ = c.Close() }()
+				br := bufio.NewReader(c)
+				for {
+					line, err := br.ReadString('\n')
+					if err != nil {
+						return
+					}
+					if line == "\r\n" || line == "\n" {
+						break
+					}
+				}
+				_, _ = c.Write([]byte(resp))
+				time.Sleep(30 * time.Millisecond)
+			}(c, resp)
+		}
+	}()
+	return "http://" + ln.Addr().String()
+}
+
+func cli(t *testing.T) (*Client, *Options) {
+	t.Helper()
+	o := *DefaultOptions
+	o.Timeout = 5 * time.Second
+	return &Client{dialer: new(dialer), Options: &o}, &o
+}
+
+func gzm(s string) string {
+	var b bytes.Buffer
+	w := gzip.NewWriter(&b)
+	_, _ = w.Write([]byte(s))
+	_ = w.Close()
+	return b.String()
+}
+
+// Field names are case insensitive (RFC 9110 s5.1). A conformant client must
+// gzip-decode and expose Content-Encoding regardless of the case the server
+// chose. These assertions encode the CORRECT behaviour; they fail on the bug.
+func TestCE(t *testing.T) {
+	const marker = "SENSITIVE-MARKER-9f3a"
+	packed := gzm(marker)
+	for _, name := range []string{"Content-Encoding", "content-encoding"} {
+		t.Run(name, func(t *testing.T) {
+			resp := "HTTP/1.1 200 OK\r\n" + name + ": gzip\r\nContent-Length: " +
+				strconv.Itoa(len(packed)) + "\r\n\r\n" + packed
+			url := rawSrv(t, resp)
+			c, o := cli(t)
+			r, err := c.DoRawWithOptions("GET", url, "/x", nil, nil, o)
+			if err != nil {
+				t.Fatalf("DoRawWithOptions: %v", err)
+			}
+			body, _ := io.ReadAll(r.Body)
+			_ = r.Body.Close()
+			t.Logf("RESULT field=%-16q bodylen=%d Get(Content-Encoding)=%q", name, len(body), r.Header.Get("Content-Encoding"))
+			if string(body) != marker {
+				t.Errorf("field %q: body=%q (len %d), want decompressed %q", name, truncHP(body), len(body), marker)
+			}
+			if got := r.Header.Get("Content-Encoding"); got != "gzip" {
+				t.Errorf("field %q: resp.Header.Get(\"Content-Encoding\")=%q, want \"gzip\" (http.Header canonical-key contract)", name, got)
+			}
+		})
+	}
+}
+
+// A conformant client follows a 302 regardless of the case of "Location".
+func TestLoc(t *testing.T) {
+	for _, name := range []string{"Location", "location"} {
+		t.Run(name, func(t *testing.T) {
+			redirect := "HTTP/1.1 302 Found\r\n" + name + ": /landing\r\nContent-Length: 0\r\n\r\n"
+			landing := "HTTP/1.1 200 OK\r\nContent-Length: 7\r\n\r\nlanded!"
+			url := rawSrv(t, redirect, landing)
+			c, o := cli(t)
+			r, err := c.DoRawWithOptions("GET", url, "/start", nil, nil, o)
+			if err != nil {
+				t.Errorf("field %q: DoRawWithOptions returned error %v; a 302 must not error", name, err)
+				return
+			}
+			body, _ := io.ReadAll(r.Body)
+			_ = r.Body.Close()
+			t.Logf("RESULT field=%-10q final_status=%d body=%q", name, r.StatusCode, body)
+			if r.StatusCode != 200 || string(body) != "landed!" {
+				t.Errorf("field %q: landed on status=%d body=%q; redirect not followed", name, r.StatusCode, body)
+			}
+		})
+	}
+}
+
+func truncHP(b []byte) string {
+	if len(b) > 24 {
+		return string(b[:24]) + "..."
+	}
+	return string(b)
+}
diff --git a/util.go b/util.go
index 288800e..49a4a7f 100644
--- a/util.go
+++ b/util.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/textproto"
 	"strings"
 
 	"github.com/projectdiscovery/rawhttp/client"
@@ -91,7 +92,8 @@ func fromHeaders(h []client.Header) map[string][]string {
 	}
 	var r = make(map[string][]string)
 	for _, hh := range h {
-		r[hh.Key] = append(r[hh.Key], hh.Value)
+		k := textproto.CanonicalMIMEHeaderKey(hh.Key)
+		r[k] = append(r[k], hh.Value)
 	}
 	return r
 }