diff --git a/cores/esp8266/spiffs_api.h b/cores/esp8266/spiffs_api.h
index 08f9eb879..4a32b8ec0 100644
--- a/cores/esp8266/spiffs_api.h
+++ b/cores/esp8266/spiffs_api.h
@@ -154,6 +154,9 @@ public:
             return;
         }
         SPIFFS_unmount(&_fs);
+        _workBuf.reset(nullptr);
+        _fdsBuf.reset(nullptr);
+        _cacheBuf.reset(nullptr);
     }
 
     bool format() override