diff --git a/src/catch2/catch_approx.hpp b/src/catch2/catch_approx.hpp
index 7c3a17c0..a46caeb5 100644
--- a/src/catch2/catch_approx.hpp
+++ b/src/catch2/catch_approx.hpp
@@ -86,14 +86,14 @@ namespace Catch {
 
         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
         Approx& epsilon( T const& newEpsilon ) {
-            double epsilonAsDouble = static_cast<double>(newEpsilon);
+            const auto epsilonAsDouble = static_cast<double>(newEpsilon);
             setEpsilon(epsilonAsDouble);
             return *this;
         }
 
         template <typename T, typename = std::enable_if_t<std::is_constructible<double, T>::value>>
         Approx& margin( T const& newMargin ) {
-            double marginAsDouble = static_cast<double>(newMargin);
+            const auto marginAsDouble = static_cast<double>(newMargin);
             setMargin(marginAsDouble);
             return *this;
         }