diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 0b024178edd3..4233cbe47052 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -533,6 +533,11 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 
 	dev = rt->dst.dev;
 
+	/* for offloaded checksums cleanup checksum before fragmentation */
+	if (skb->ip_summed == CHECKSUM_PARTIAL &&
+	    (err = skb_checksum_help(skb)))
+		goto fail;
+
 	/*
 	 *	Point into the IP datagram header.
 	 */
@@ -657,9 +662,6 @@ slow_path_clean:
 	}
 
 slow_path:
-	/* for offloaded checksums cleanup checksum before fragmentation */
-	if ((skb->ip_summed == CHECKSUM_PARTIAL) && skb_checksum_help(skb))
-		goto fail;
 	iph = ip_hdr(skb);
 
 	left = skb->len - hlen;		/* Space per frame */