diff --git a/cores/esp8266/FileSystem.cpp b/cores/esp8266/FileSystem.cpp
index f2517cf98..d94af10ac 100755
--- a/cores/esp8266/FileSystem.cpp
+++ b/cores/esp8266/FileSystem.cpp
@@ -162,7 +162,8 @@ int FSFile::available() {
 
 size_t FSFile::write(const uint8_t *buf, size_t size){
   if (! _file) return 0;
-  return SPIFFS_write(&_filesystemStorageHandle, _file, (uint8_t *)buf, size);
+  int res = SPIFFS_write(&_filesystemStorageHandle, _file, (uint8_t *)buf, size);
+  return (res > 0)?res:0;
 }
 
 size_t FSFile::write(uint8_t val) {