diff --git a/sys/netgraph7/ng_pred1.c b/sys/netgraph7/ng_pred1.c
--- a/sys/netgraph7/ng_pred1.c
+++ b/sys/netgraph7/ng_pred1.c
@@ -394,7 +394,7 @@
 	priv->stats.InOctets += inlen;
 
 	/* Reserve space for expansion. */
-	if (inlen > (PRED1_BUF_SIZE*8/9 + 1 + 4)) {
+	if (inlen > (PRED1_BUF_SIZE*8/9)) { /* leave expansion+checksum headroom */
 		priv->stats.Errors++;
 		NG_FREE_M(m);
 		return (ENOMEM);