diff --git a/src/test-map.cc b/src/test-map.cc
index d8b8d531c..8c167b1da 100644
--- a/src/test-map.cc
+++ b/src/test-map.cc
@@ -100,9 +100,9 @@ main (int argc, char **argv)
 
   /* Test class key / value types. */
   {
-    hb_hashmap_t<hb_bytes_t, int, nullptr_t, int, nullptr, 0> m1;
-    hb_hashmap_t<int, hb_bytes_t, int, nullptr_t, 0, nullptr> m2;
-    hb_hashmap_t<hb_bytes_t, hb_bytes_t, nullptr_t, nullptr_t, nullptr, nullptr> m3;
+    hb_hashmap_t<hb_bytes_t, int, std::nullptr_t, int, nullptr, 0> m1;
+    hb_hashmap_t<int, hb_bytes_t, int, std::nullptr_t, 0, nullptr> m2;
+    hb_hashmap_t<hb_bytes_t, hb_bytes_t, std::nullptr_t, std::nullptr_t, nullptr, nullptr> m3;
     assert (m1.get_population () == 0);
     assert (m2.get_population () == 0);
     assert (m3.get_population () == 0);