--- a/include/pqxx/compiler-internal.hxx
+++ b/include/pqxx/compiler-internal.hxx
@@ -76,7 +76,7 @@
 namespace internal
 {
 /// Wrapper for std::distance; not all platforms have std::distance().
-template<typename T> inline ptrdiff_t distance(T first, T last)
+template<typename T> inline PGSTD::ptrdiff_t distance(T first, T last)
 {
 #ifdef PQXX_HAVE_DISTANCE
   return PGSTD::distance(first, last);
--- a/test/unit/test_escape.cxx
+++ b/test/unit/test_escape.cxx
@@ -54,8 +54,8 @@
   PQXX_CHECK_EQUAL(t.quote("x"), "'x'", "Basic quote() fails.");
   PQXX_CHECK_EQUAL(t.quote(1), "'1'", "quote() not dealing with int properly.");
   PQXX_CHECK_EQUAL(t.quote(0), "'0'", "Quoting zero is a problem.");
-  const char *const nullptr = NULL;
-  PQXX_CHECK_EQUAL(t.quote(nullptr), "NULL", "Not quoting NULL correctly.");
+  const char *const null_ptr = NULL;
+  PQXX_CHECK_EQUAL(t.quote(null_ptr), "NULL", "Not quoting NULL correctly.");
   PQXX_CHECK_EQUAL(t.quote(string("'")), "''''", "Escaping quotes goes wrong.");
 
   PQXX_CHECK_EQUAL(t.quote("x"),