diff --git a/cores/esp8266/FileSystem.h b/cores/esp8266/FileSystem.h
index 7a4563357..460595cf3 100755
--- a/cores/esp8266/FileSystem.h
+++ b/cores/esp8266/FileSystem.h
@@ -80,7 +80,7 @@ public:
 class FSClass {
 
 private:
-  bool _mounted;
+  bool _mounted = false;
   
 public:
   bool mount();