diff --git a/esphome/components/api/proto.h b/esphome/components/api/proto.h
index cda772005b..8fb05cd6ef 100644
--- a/esphome/components/api/proto.h
+++ b/esphome/components/api/proto.h
@@ -597,6 +597,7 @@ class ProtoEncode {
     return buffer.get_pos();
   }
 };
+#undef PROTO_OUTLINE_FOR_SIZE
 
 #ifdef HAS_PROTO_MESSAGE_DUMP
 /**