diff --git a/cores/esp8266/WString.cpp b/cores/esp8266/WString.cpp
index 6f2134e86f..c81b594d6c 100644
--- a/cores/esp8266/WString.cpp
+++ b/cores/esp8266/WString.cpp
@@ -113,10 +113,7 @@ String::String(double value, unsigned char decimalPlaces) {
 }
 
 String::~String() {
-    if(buffer) {
-        free(buffer);
-    }
-    init();
+    invalidate();
 }
 
 // /*********************************************/