diff --git a/config.go b/config.go
index 73484d7..53bfd05 100644
--- a/config.go
+++ b/config.go
@@ -385,7 +385,7 @@ func (uc *UpstreamConfig) VerifyDomain() string {
 }
 
 // UpstreamSendClientInfo reports whether the upstream is
-// configured to send client info to Control D DNS server.
+// configured to send client info to the DNS server.
 //
 // Client info includes:
 //   - MAC
diff --git a/doh.go b/doh.go
index 3459cb8..314ef15 100644
--- a/doh.go
+++ b/doh.go
@@ -159,6 +159,9 @@ func addHeader(ctx context.Context, req *http.Request, uc *UpstreamConfig) {
 				dohHeader = newControlDHeaders(ci)
 			case uc.isNextDNS():
 				dohHeader = newNextDNSHeaders(ci)
+		        default:
+			     // For custom upstreams with send_client_info enabled, use ControlD-style headers	
+			     dohHeader = newControlDHeaders(ci)
 			}
 		}
 	}