diff --git a/mos.yml b/mos.yml
index 35079c0..a7b4454 100644
--- a/mos.yml
+++ b/mos.yml
@@ -13,6 +13,7 @@ includes:
 
 cdefs:
   ARDUINO: 150
+  RH_PLATFORM: RH_PLATFORM_ESP8266
 
 tags:
   - arduino