Index: sys/kern/kern_sendfile.c
===================================================================
--- sys/kern/kern_sendfile.c
+++ sys/kern/kern_sendfile.c
@@ -866,8 +866,11 @@
 		CURVNET_RESTORE();
 
 		m = NULL;	/* pru_send always consumes */
-		if (error)
+		if (error) {
+			if (error == EAGAIN)
+				sbytes += space + hdrlen;
 			goto done;
+		}
 		sbytes += space + hdrlen;
 		if (hdrlen)
 			hdrlen = 0;