diff --git a/src/catch2/internal/catch_errno_guard.hpp b/src/catch2/internal/catch_errno_guard.hpp
index b1d1fc1c..810ca99f 100644
--- a/src/catch2/internal/catch_errno_guard.hpp
+++ b/src/catch2/internal/catch_errno_guard.hpp
@@ -9,8 +9,12 @@
 
 namespace Catch {
 
+    //! Simple RAII class that stores the value of `errno`
+    //! at construction and restores it at destruction.
     class ErrnoGuard {
     public:
+        // Keep these outlined to avoid dragging in macros from <cerrno>
+
         ErrnoGuard();
         ~ErrnoGuard();
     private: