diff --git a/libraries/ESP8266WiFi/src/include/ClientContext.h b/libraries/ESP8266WiFi/src/include/ClientContext.h
index d1f728eef..619356862 100644
--- a/libraries/ESP8266WiFi/src/include/ClientContext.h
+++ b/libraries/ESP8266WiFi/src/include/ClientContext.h
@@ -90,12 +90,15 @@ class ClientContext {
         }
 
         void unref() {
-            DEBUGV(":ur %d\r\n", _refcnt);
-            if(--_refcnt == 0) {
-                flush();
-                close();
-                if(_discard_cb) _discard_cb(_discard_cb_arg, this);
-                delete this;
+            if(this != 0) {
+                DEBUGV(":ur %d\r\n", _refcnt);
+                if(--_refcnt == 0) {
+                    flush();
+                    close();
+                    if(_discard_cb)
+                        _discard_cb(_discard_cb_arg, this);
+                    delete this;
+                }
             }
         }
         
diff --git a/libraries/ESP8266WiFi/src/include/UdpContext.h b/libraries/ESP8266WiFi/src/include/UdpContext.h
index c86e050ed..f7cebc86c 100644
--- a/libraries/ESP8266WiFi/src/include/UdpContext.h
+++ b/libraries/ESP8266WiFi/src/include/UdpContext.h
@@ -77,10 +77,11 @@ public:
 
     void unref()
     {
-        DEBUGV(":ur %d\r\n", _refcnt);
-        if (--_refcnt == 0)
-        {
-            delete this;
+        if(this != 0) {
+            DEBUGV(":ur %d\r\n", _refcnt);
+            if(--_refcnt == 0) {
+                delete this;
+            }
         }
     }