diff --git a/include/nlohmann/optional.hpp b/include/nlohmann/optional.hpp
index f39d2d7ba..563897625 100644
--- a/include/nlohmann/optional.hpp
+++ b/include/nlohmann/optional.hpp
@@ -65,7 +65,7 @@ class optional
             is_base_constructible_from<std::in_place_t, U...>
         >;
 
-    struct noexcept_fix_t {};
+    struct noexcept_fix_t {}; // trick for GCC8.1 (see default constructor)
 
     base_type base_value;
 
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index bce245c98..a02d2a6c5 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -4657,7 +4657,7 @@ class optional
             is_base_constructible_from<std::in_place_t, U...>
         >;
 
-    struct noexcept_fix_t {};
+    struct noexcept_fix_t {}; // trick for GCC8.1 (see default constructor)
 
     base_type base_value;