diff --git a/src/core/tcp_out.c b/src/core/tcp_out.c
index dff3f210..65328c2e 100644
--- a/src/core/tcp_out.c
+++ b/src/core/tcp_out.c
@@ -538,7 +538,8 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
         /* If the last unsent pbuf is of type PBUF_ROM, try to extend it. */
         struct pbuf *p;
         for (p = last_unsent->p; p->next != NULL; p = p->next);
-        if (p->type == PBUF_ROM && (const u8_t *)p->payload + p->len == (const u8_t *)arg) {
+        if (p->type == PBUF_ROM &&
+            (const u8_t *)p->payload + p->len == (const u8_t *)arg) {
           LWIP_ASSERT("tcp_write: ROM pbufs cannot be oversized", pos == 0);
           extendlen = seglen;
         } else {