diff --git a/writeto.go b/writeto.go
index faf6124..2577fe4 100644
--- a/writeto.go
+++ b/writeto.go
@@ -258,6 +258,10 @@ func (w *messageWriter) writeHeaders(h map[string][]string) {
 }
 
 func (w *messageWriter) writeBody(f func(io.Writer) error, enc Encoding) {
+	if w.err != nil {
+		return
+	}
+
 	var subWriter io.Writer
 	if w.depth == 0 {
 		w.writeString("\r\n")