diff --git a/src/AutoConnect.h b/src/AutoConnect.h
index 35af7f0..d580a9a 100644
--- a/src/AutoConnect.h
+++ b/src/AutoConnect.h
@@ -240,6 +240,7 @@ class AutoConnect {
   static unsigned int  _toWiFiQuality(int32_t rssi);
   DetectExit_ft        _onDetectExit;
   WebServerClass::THandlerFunction _notFoundHandler;
+  size_t               _freeHeapSize;
 
   /** Servers which works in concert. */
   std::unique_ptr<WebServerClass> _webServer;