diff --git a/src/openvic-simulation/types/TypedSpan.hpp b/src/openvic-simulation/types/TypedSpan.hpp
index 957f31aa..f59730e8 100644
--- a/src/openvic-simulation/types/TypedSpan.hpp
+++ b/src/openvic-simulation/types/TypedSpan.hpp
@@ -18,7 +18,7 @@ namespace OpenVic {
 		using utility::forwardable_span<ValueType, _Extent>::forwardable_span;
 
 		constexpr IndexType size() const {
-			return IndexType(std::span<ValueType, _Extent>::size());
+			return IndexType(utility::forwardable_span<ValueType, _Extent>::size());
 		}
 
 		constexpr utility::forwardable_span<ValueType, _Extent>::reference operator[](const IndexType _Off) const {