diff --git a/region.cpp b/region.cpp
index f254eb71..1b465b19 100644
--- a/region.cpp
+++ b/region.cpp
@@ -53,24 +53,6 @@ cruft::region<S,T>::region (point_t _a,
 }
 
 
-//-----------------------------------------------------------------------------
-template <size_t S, typename T>
-T
-cruft::region<S,T>::area (void) const
-{
-    return e.area ();
-}
-
-
-//-----------------------------------------------------------------------------
-template <size_t S, typename T>
-T
-cruft::region<S,T>::diameter (void) const
-{
-    return e.diameter ();
-}
-
-
 //-----------------------------------------------------------------------------
 template <size_t S, typename T>
 typename cruft::region<S,T>::extent_t
diff --git a/region.hpp b/region.hpp
index 025e2116..7daf33d2 100644
--- a/region.hpp
+++ b/region.hpp
@@ -52,8 +52,8 @@ namespace cruft {
         }
 
         //---------------------------------------------------------------------
-        T area (void) const;
-        T diameter (void) const;
+        constexpr T area (void) const { return e.area (); }
+        constexpr T diameter (void) const { return e.diameter (); }
         extent_t magnitude (void) const;
         extent_t magnitude (extent_t);