diff --git a/src/core/pbuf.c b/src/core/pbuf.c
index 25470863..d93e9eea 100644
--- a/src/core/pbuf.c
+++ b/src/core/pbuf.c
@@ -128,11 +128,10 @@ pbuf_free_ooseq(void)
   SYS_ARCH_SET(pbuf_free_ooseq_pending, 0);
 
   for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
-    if (NULL != pcb->ooseq) {
+    if (pcb->ooseq != NULL) {
       /** Free the ooseq pbufs of one PCB only */
       LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
-      tcp_segs_free(pcb->ooseq);
-      pcb->ooseq = NULL;
+      tcp_free_ooseq(pcb);
       return;
     }
   }
diff --git a/src/core/tcp.c b/src/core/tcp.c
index 7ba5c396..52ec121d 100644
--- a/src/core/tcp.c
+++ b/src/core/tcp.c
@@ -1176,12 +1176,8 @@ tcp_slowtmr_start:
 #if TCP_QUEUE_OOSEQ
     if (pcb->ooseq != NULL &&
         (tcp_ticks - pcb->tmr >= (u32_t)pcb->rto * TCP_OOSEQ_TIMEOUT)) {
-      tcp_segs_free(pcb->ooseq);
-      pcb->ooseq = NULL;
       LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: dropping OOSEQ queued data\n"));
-#if LWIP_TCP_SACK_OUT
-      memset(pcb->rcv_sacks, 0, sizeof(pcb->rcv_sacks));
-#endif /* LWIP_TCP_SACK_OUT */
+      tcp_free_ooseq(pcb);
     }
 #endif /* TCP_QUEUE_OOSEQ */
 
@@ -1888,12 +1884,8 @@ tcp_pcb_purge(struct tcp_pcb *pcb)
 #if TCP_QUEUE_OOSEQ
     if (pcb->ooseq != NULL) {
       LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->ooseq\n"));
+      tcp_free_ooseq(pcb);
     }
-    tcp_segs_free(pcb->ooseq);
-    pcb->ooseq = NULL;
-#if LWIP_TCP_SACK_OUT
-    memset(pcb->rcv_sacks, 0, sizeof(pcb->rcv_sacks));
-#endif /* LWIP_TCP_SACK_OUT */
 #endif /* TCP_QUEUE_OOSEQ */
 
     /* Stop the retransmission timer as it will expect data on unacked
@@ -2113,6 +2105,19 @@ tcp_tcp_get_tcp_addrinfo(struct tcp_pcb *pcb, int local, ip_addr_t *addr, u16_t
   return ERR_VAL;
 }
 
+/* Free all ooseq pbufs (and possibly reset SACK state) */
+void
+tcp_free_ooseq(struct tcp_pcb *pcb)
+{
+  if (pcb->ooseq) {
+    tcp_segs_free(pcb->ooseq);
+    pcb->ooseq = NULL;
+#if LWIP_TCP_SACK_OUT
+    memset(pcb->rcv_sacks, 0, sizeof(pcb->rcv_sacks));
+#endif /* LWIP_TCP_SACK_OUT */
+  }
+}
+
 #if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG
 /**
  * Print a tcp header for debugging purposes.
diff --git a/src/include/lwip/priv/tcp_priv.h b/src/include/lwip/priv/tcp_priv.h
index 1670805c..b1d382f2 100644
--- a/src/include/lwip/priv/tcp_priv.h
+++ b/src/include/lwip/priv/tcp_priv.h
@@ -502,6 +502,10 @@ void tcp_timer_needed(void);
 
 void tcp_netif_ip_addr_changed(const ip_addr_t* old_addr, const ip_addr_t* new_addr);
 
+#if TCP_QUEUE_OOSEQ
+void tcp_free_ooseq(struct tcp_pcb *pcb);
+#endif
+
 #ifdef __cplusplus
 }
 #endif