diff --git a/libraries/ESP8266WiFi/src/include/UdpContext.h b/libraries/ESP8266WiFi/src/include/UdpContext.h
index cb527ab0af..95f3420809 100644
--- a/libraries/ESP8266WiFi/src/include/UdpContext.h
+++ b/libraries/ESP8266WiFi/src/include/UdpContext.h
@@ -288,7 +288,8 @@ class UdpContext
                 data_size -= will_copy;
             }
         }
-        pbuf_free(_tx_buf_head);
+        if (_tx_buf_head)
+            pbuf_free(_tx_buf_head);
         _tx_buf_head = 0;
         _tx_buf_cur = 0;
         _tx_buf_offset = 0;