diff --git a/region.cpp b/region.cpp
index aa6d41e5..c076a273 100644
--- a/region.cpp
+++ b/region.cpp
@@ -335,8 +335,6 @@ util::operator<< (std::ostream &os, const util::region<T> &rhs) {
 
 //-----------------------------------------------------------------------------
 namespace util {
-    template struct region<int32_t>;
-    template struct region<int64_t>;
     template struct region<uint32_t>;
     template struct region<uint64_t>;
     template struct region<float>;
diff --git a/region.hpp b/region.hpp
index 9c6d1ec7..3af41a92 100644
--- a/region.hpp
+++ b/region.hpp
@@ -31,8 +31,8 @@ namespace util {
      */
     template <typename T>
     struct region {
-        typedef T position_type;
-        typedef T size_type;
+        using position_type = T;
+        using size_type = typename try_unsigned<T>::type;
 
         static constexpr size_t dimension = 2u;
         static constexpr size_t elements = dimension * 2;
diff --git a/test/region.cpp b/test/region.cpp
index aefe5b30..7c86a490 100644
--- a/test/region.cpp
+++ b/test/region.cpp
@@ -21,13 +21,13 @@ main (int, char **) {
     CHECK_EQ (region<double>::UNIT.area (), 1.0);
     CHECK_EQ (region< float>::UNIT.area (), 1.0f);
 
-    CHECK (region<int> (0, 0, 2, 2).includes (point<2,int>(1, 1)));
-    CHECK (region<int> (0, 0, 2, 2).includes (point<2,int>(0, 0)));
-    CHECK (region<int> (0, 0, 2, 2).includes (point<2,int>(2, 2)));
+    CHECK (region<unsigned> (0, 0, 2, 2).includes (point<2,unsigned>(1, 1)));
+    CHECK (region<unsigned> (0, 0, 2, 2).includes (point<2,unsigned>(0, 0)));
+    CHECK (region<unsigned> (0, 0, 2, 2).includes (point<2,unsigned>(2, 2)));
 
-    CHECK ( region<int> (0, 0, 2, 2).contains (point<2,int>(1, 1)));
-    CHECK (!region<int> (0, 0, 2, 2).contains (point<2,int>(0, 0)));
-    CHECK (!region<int> (0, 0, 2, 2).contains (point<2,int>(2, 2)));
+    CHECK ( region<unsigned> (0, 0, 2, 2).contains (point<2,unsigned>(1, 1)));
+    CHECK (!region<unsigned> (0, 0, 2, 2).contains (point<2,unsigned>(0, 0)));
+    CHECK (!region<unsigned> (0, 0, 2, 2).contains (point<2,unsigned>(2, 2)));
 
     //CHECK (region<intmax_t> (0, 0, 10, 10).includes (point2d (0.4, 0.01)));
     //CHECK (region<intmax_t> (0, 0, 10, 10).contains (point2d (0.4, 0.01)));