diff --git a/testing/fix-macros.h b/testing/fix-macros.h
index 0ba58308..a6a63c81 100644
--- a/testing/fix-macros.h
+++ b/testing/fix-macros.h
@@ -15,9 +15,8 @@
  */
 
 // No `#pragma once` since these undefs need to have every time a Kaleidoscope/
-// Arduino header is included before non-Kaleidoscope/Arduino header.
-// #pragma once
-
+// Arduino header is included before non-Kaleidoscope/Arduino header. The undefs
+// are needed, due to naming conflicts between Arduino and Googletest.
 
 #undef min
 #undef max