diff --git a/reactos/lib/drivers/oskittcp/oskittcp/tcp_subr.c b/reactos/lib/drivers/oskittcp/oskittcp/tcp_subr.c
index 4632b688ef1..e3557eea13e 100644
--- a/reactos/lib/drivers/oskittcp/oskittcp/tcp_subr.c
+++ b/reactos/lib/drivers/oskittcp/oskittcp/tcp_subr.c
@@ -163,6 +163,7 @@ tcp_respond(tp, ti, m, ack, seq, flags)
 	tcp_seq ack, seq;
 	int flags;
 {
+	struct mbuf *n;
 	register int tlen;
 	int win = 0;
 	struct route *ro = 0;
@@ -221,6 +222,18 @@ tcp_respond(tp, ti, m, ack, seq, flags)
 		tcp_trace(TA_OUTPUT, 0, tp, ti, 0);
 #endif
 	(void) ip_output(m, NULL, ro, 0, NULL);
+#ifdef __REACTOS__
+	/* We allocated m, so we are responsible for freeing it. If the mbuf
+           contains a pointer to an external datablock, we (or rather, m_copy)
+           didn't allocate it but pointed it to the data to send. So we have
+           to cheat a little bit and keep M_FREE from freeing the external
+           data block */
+	while (NULL != m) {
+	    m->m_flags &= ~M_EXT;
+	    MFREE(m, n);
+	    m = n;
+	}
+#endif
 }
 
 /*