Index: uspace/srv/inet/pdu.c
===================================================================
--- uspace/srv/inet/pdu.c	(revision 7f95c90417b96f547cf46abd21293504c85a9293)
+++ uspace/srv/inet/pdu.c	(revision 7fda2e083e83e11956b6f1c016bf5aa164c3e1b1)
@@ -141,8 +141,8 @@
 	/* Amount of space in the PDU available for payload */
 	spc_avail = mtu - hdr_size;
+	spc_avail -= (spc_avail % FRAG_OFFS_UNIT);
 
 	/* Amount of data (payload) to transfer */
 	xfer_size = min(packet->size - offs, spc_avail);
-	xfer_size -= (xfer_size % FRAG_OFFS_UNIT);
 
 	/* Total PDU size */