diff --git a/VERSION b/VERSION
index 4671dc9d..887852f8 100644
--- a/VERSION
+++ b/VERSION
@@ -13,7 +13,7 @@ gwen:
 gitlab:
     espconn:    3a998034
     freertos:   ac047746
-    lwip:       94e6ac0e
+    lwip:       bfdb6ec2
     driver:     7bee5263
     mbedtls:    1ac9f1f4
     ssl:        eefb383a
\ No newline at end of file
diff --git a/lib/liblwip.a b/lib/liblwip.a
index 609f2e75..c347c282 100644
Binary files a/lib/liblwip.a and b/lib/liblwip.a differ
diff --git a/third_party/lwip/core/pbuf.c b/third_party/lwip/core/pbuf.c
index 54a81e29..d7c4ec8b 100644
--- a/third_party/lwip/core/pbuf.c
+++ b/third_party/lwip/core/pbuf.c
@@ -392,6 +392,11 @@ pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
   /* set flags */
   p->flags = 0;
   LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
+
+  if ((int)p > 0x40000000) {
+      pbuf_free(p);
+      p = NULL;
+  }
   return p;
 }