diff --git a/proxy/http/request.go b/proxy/http/request.go
index 84f3fe4..6a6b75a 100644
--- a/proxy/http/request.go
+++ b/proxy/http/request.go
@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"bytes"
 	"fmt"
+	"net"
 	"net/textproto"
 	"net/url"
 	"strings"
@@ -78,24 +79,19 @@ func parseRequest(r *bufio.Reader) (*request, error) {
 		uri = uri[7:]
 	}
 
-	tgt := u.Host
-	if !strings.Contains(tgt, ":") {
-		tgt += ":80"
-	}
-
 	req := &request{
 		method: method,
 		uri:    uri,
 		proto:  proto,
 		auth:   auth,
 		header: header,
-		target: tgt,
 	}
 
 	if u.IsAbs() {
 		req.absuri = u.String()
-		u.Scheme, u.Host = "", ""
-		req.ruri = u.String()
+		relative := *u
+		relative.Scheme, relative.Host = "", ""
+		req.ruri = relative.String()
 	} else {
 		req.ruri = u.String()
 		base, err := url.Parse("http://" + header.Get("Host"))
@@ -106,6 +102,12 @@ func parseRequest(r *bufio.Reader) (*request, error) {
 		req.absuri = u.String()
 	}
 
+	port := u.Port()
+	if port == "" {
+		port = "80"
+	}
+	req.target = net.JoinHostPort(u.Hostname(), port)
+
 	return req, nil
 }
 
diff --git a/proxy/http/request_test.go b/proxy/http/request_test.go
new file mode 100644
index 0000000..fc5e923
--- /dev/null
+++ b/proxy/http/request_test.go
@@ -0,0 +1,54 @@
+package http
+
+import (
+	"bufio"
+	"strings"
+	"testing"
+)
+
+func TestParseRequestTarget(t *testing.T) {
+	for _, tt := range []struct {
+		name   string
+		uri    string
+		host   string
+		target string
+	}{
+		{"absolute hostname", "http://example.com/path", "other.example", "example.com:80"},
+		{"absolute hostname port", "http://example.com:8080/path", "other.example", "example.com:8080"},
+		{"absolute IPv6", "http://[2001:db8::1]/path", "other.example", "[2001:db8::1]:80"},
+		{"absolute IPv6 port", "http://[2001:db8::1]:8080/path", "other.example", "[2001:db8::1]:8080"},
+		{"origin hostname", "/path", "example.com", "example.com:80"},
+		{"origin hostname port", "/path", "example.com:8080", "example.com:8080"},
+		{"origin IPv6", "/path", "[2001:db8::1]", "[2001:db8::1]:80"},
+		{"origin IPv6 port", "/path", "[2001:db8::1]:8080", "[2001:db8::1]:8080"},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			raw := "GET " + tt.uri + " HTTP/1.1\r\nHost: " + tt.host + "\r\n\r\n"
+			req, err := parseRequest(bufio.NewReader(strings.NewReader(raw)))
+			if err != nil {
+				t.Fatal(err)
+			}
+			if req.target != tt.target {
+				t.Errorf("target = %q, want %q", req.target, tt.target)
+			}
+			if req.ruri != "/path" {
+				t.Errorf("relative URI = %q, want /path", req.ruri)
+			}
+		})
+	}
+}
+
+func TestParseConnectAuthority(t *testing.T) {
+	for _, authority := range []string{"example.com:443", "[2001:db8::1]:8443"} {
+		t.Run(authority, func(t *testing.T) {
+			raw := "CONNECT " + authority + " HTTP/1.1\r\nHost: other.example:8080\r\n\r\n"
+			req, err := parseRequest(bufio.NewReader(strings.NewReader(raw)))
+			if err != nil {
+				t.Fatal(err)
+			}
+			if req.uri != authority || req.target != authority {
+				t.Errorf("CONNECT uri=%q target=%q, want %q", req.uri, req.target, authority)
+			}
+		})
+	}
+}