diff --git a/provider/activitypub/mastodon/client.go b/provider/activitypub/mastodon/client.go
index 529b477c..db18cda5 100644
--- a/provider/activitypub/mastodon/client.go
+++ b/provider/activitypub/mastodon/client.go
@@ -11,7 +11,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"net"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -159,30 +158,39 @@ func NewClient(ctx context.Context, endpoint string, relayList []string, errorCh
 	return c, nil
 }
 
-// parseEndpoint splits a URL endpoint into its hostname and port components.
-func parseEndpoint(endpoint string) (hostname string, port int64, err error) {
-	parsedHostname := strings.TrimPrefix(endpoint, "https://")
-
-	zap.L().Info("Parsed hostname", zap.String("parsedHostname", parsedHostname))
+// parseEndpoint splits a URL endpoint into its domain (with protocol) and port components.
+func parseEndpoint(endpoint string) (domain string, port int64, err error) {
+	// check if the endpoint starts with 'https://'
+	if !strings.HasPrefix(endpoint, "https://") {
+		return "", 0, fmt.Errorf("invalid endpoint format: must start with 'https://' in '%s'", endpoint)
+	}
 
-	// Check if the host contains a port
-	if !strings.Contains(parsedHostname, ":") {
-		return "", 0, fmt.Errorf("invalid host:port format: missing port in '%s'", parsedHostname)
+	// check if the endpoint contains a colon
+	if !strings.Contains(endpoint, ":") {
+		return "", 0, fmt.Errorf("invalid host:port format: missing port in '%s'", endpoint)
 	}
 
-	// Split the hostname and port
-	parsedHostname, hostPortInStr, err := net.SplitHostPort(parsedHostname)
-	if err != nil {
-		return "", 0, fmt.Errorf("invalid host:port format: %w", err)
+	// split the endpoint into domain and port
+	parts := strings.Split(endpoint, ":")
+	// https: + domain + port
+	if len(parts) != 3 {
+		return "", 0, fmt.Errorf("invalid endpoint format in '%s'", endpoint)
 	}
 
-	// Convert the port to int64
-	parsedPort, err := strconv.ParseInt(hostPortInStr, 10, 64)
+	// reconstruct the protocol header and domain
+	domain = parts[0] + ":" + parts[1]
+
+	// parse the port
+	parsedPort, err := strconv.ParseInt(parts[2], 10, 64)
 	if err != nil {
 		return "", 0, fmt.Errorf("invalid port value: %w", err)
 	}
 
-	return parsedHostname, parsedPort, nil
+	zap.L().Info("Parsed endpoint",
+		zap.String("domain", domain),
+		zap.Int64("port", parsedPort))
+
+	return domain, parsedPort, nil
 }
 
 // initializeServer initializes an echo http server