diff --git a/src/core/include/units/quantity.h b/src/core/include/units/quantity.h
index 684eb614..4ed10cf9 100644
--- a/src/core/include/units/quantity.h
+++ b/src/core/include/units/quantity.h
@@ -115,7 +115,7 @@ public:
   using dimension = D;
   using unit = U;
   using rep = Rep;
-  static constexpr units::reference<D, U> reference{};
+  static constexpr units::reference<dimension, unit> reference{};
 
   // static member functions
   [[nodiscard]] static constexpr quantity zero() noexcept
diff --git a/src/core/include/units/quantity_kind.h b/src/core/include/units/quantity_kind.h
index be3f01ad..c6891bd2 100644
--- a/src/core/include/units/quantity_kind.h
+++ b/src/core/include/units/quantity_kind.h
@@ -83,7 +83,7 @@ public:
   using dimension = typename quantity_type::dimension;
   using unit = typename quantity_type::unit;
   using rep = typename quantity_type::rep;
-  static constexpr units::reference<D, U> reference{};
+  static constexpr units::reference<dimension, unit> reference{};
 
 private:
   quantity_type q_;
diff --git a/src/core/include/units/quantity_point.h b/src/core/include/units/quantity_point.h
index 77d4e422..dd1a276f 100644
--- a/src/core/include/units/quantity_point.h
+++ b/src/core/include/units/quantity_point.h
@@ -49,7 +49,7 @@ public:
   using dimension = typename quantity_type::dimension;
   using unit = typename quantity_type::unit;
   using rep = typename quantity_type::rep;
-  static constexpr units::reference<D, U> reference{};
+  static constexpr units::reference<dimension, unit> reference{};
 
 private:
   quantity_type q_{};
diff --git a/src/core/include/units/quantity_point_kind.h b/src/core/include/units/quantity_point_kind.h
index f2d2d716..e315ff40 100644
--- a/src/core/include/units/quantity_point_kind.h
+++ b/src/core/include/units/quantity_point_kind.h
@@ -50,7 +50,7 @@ public:
   using dimension = typename quantity_type::dimension;
   using unit = typename quantity_type::unit;
   using rep = typename quantity_type::rep;
-  static constexpr units::reference<D, U> reference{};
+  static constexpr units::reference<dimension, unit> reference{};
 
 private:
   quantity_kind_type qk_;