diff --git a/platformio.ini b/platformio.ini
index 60ec90b8..c684b57c 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -184,7 +184,8 @@ build_flags =
   -DESP8266
   -DFP_IN_IROM
   ;-Wno-deprecated-declarations
-  ;-Wno-register
+  -Wno-register  ;; leaves some warnings when compiling C files: command-line option '-Wno-register' is valid for C++/ObjC++ but not for C
+  ;-Dregister= # remove warnings in C++17 due to use of deprecated register keyword by the FastLED library ;; warning: this can be dangerous
 	-Wno-misleading-indentation
 ; NONOSDK22x_190703 = 2.2.2-dev(38a443e)
   -DPIO_FRAMEWORK_ARDUINO_ESPRESSIF_SDK22x_190703