diff --git a/include/nlohmann/detail/view/builder.hpp b/include/nlohmann/detail/view/builder.hpp
index 2e0151b31..8393b9c8d 100644
--- a/include/nlohmann/detail/view/builder.hpp
+++ b/include/nlohmann/detail/view/builder.hpp
@@ -195,8 +195,9 @@ class builder
     {
         const std::uint64_t done = static_cast<std::uint64_t>(at - b) + 1;
         const std::uint64_t guess = static_cast<std::uint64_t>(n) * static_cast<std::uint64_t>(e - b + 1) / done;
+        const std::uint64_t grown = guess + (guess / 4) + 64; // a variable: GCC calls a cast of the sum useless where std::uint64_t is std::size_t
         doc.tape_size = n;
-        doc.reserve((std::max)(static_cast<std::size_t>(guess + (guess / 4) + 64), n + (n / 2) + 64));
+        doc.reserve((std::max)(static_cast<std::size_t>(grown), n + (n / 2) + 64));
         return doc.tape;
     }
 
diff --git a/single_include/nlohmann/json_view.hpp b/single_include/nlohmann/json_view.hpp
index 32b561f58..bc5391894 100644
--- a/single_include/nlohmann/json_view.hpp
+++ b/single_include/nlohmann/json_view.hpp
@@ -736,8 +736,9 @@ class builder
     {
         const std::uint64_t done = static_cast<std::uint64_t>(at - b) + 1;
         const std::uint64_t guess = static_cast<std::uint64_t>(n) * static_cast<std::uint64_t>(e - b + 1) / done;
+        const std::uint64_t grown = guess + (guess / 4) + 64; // a variable: GCC calls a cast of the sum useless where std::uint64_t is std::size_t
         doc.tape_size = n;
-        doc.reserve((std::max)(static_cast<std::size_t>(guess + (guess / 4) + 64), n + (n / 2) + 64));
+        doc.reserve((std::max)(static_cast<std::size_t>(grown), n + (n / 2) + 64));
         return doc.tape;
     }