diff --git a/src/paxcounter.conf b/src/paxcounter.conf
index 9e550d01..31423a3c 100644
--- a/src/paxcounter.conf
+++ b/src/paxcounter.conf
@@ -1,6 +1,8 @@
 // ----- Paxcounter user config file ------
 //
 // --> adapt to your needs and use case <--
+//
+// Note: After editing, before "build", use "clean" button in PlatformIO!
 
 // Verbose enables serial output
 #define VERBOSE                         1       // comment out to silence the device, for mute use build option