diff --git a/lib/fizzy/execute.cpp b/lib/fizzy/execute.cpp
index 4d59682d7..1aa84002c 100644
--- a/lib/fizzy/execute.cpp
+++ b/lib/fizzy/execute.cpp
@@ -361,17 +361,17 @@ inline bool store_into_memory(
 template <typename Op>
 inline void unary_op(OperandStack& stack, Op op) noexcept
 {
-    using T = decltype(op(stack.top()));
-    stack.top() = op(static_cast<T>(stack.top()));
+    using T = decltype(op({}));
+    stack.top() = op(stack.top().as<T>());
 }
 
 template <typename Op>
 inline void binary_op(OperandStack& stack, Op op) noexcept
 {
-    using T = decltype(op(stack.top(), stack.top()));
-    const auto val2 = static_cast<T>(stack.pop());
-    const auto val1 = static_cast<T>(stack.top());
-    stack.top() = static_cast<std::make_unsigned_t<T>>(op(val1, val2));
+    using T = decltype(op({}, {}));
+    const auto val2 = stack.pop().as<T>();
+    const auto val1 = stack.top().as<T>();
+    stack.top() = op(val1, val2);
 }
 
 template <typename T, template <typename> class Op>