diff --git a/src/test-map.cc b/src/test-map.cc
index 8c8f0a83b..d8b8d531c 100644
--- a/src/test-map.cc
+++ b/src/test-map.cc
@@ -103,6 +103,9 @@ main (int argc, char **argv)
     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;
+    assert (m1.get_population () == 0);
+    assert (m2.get_population () == 0);
+    assert (m3.get_population () == 0);
   }
 
   return 0;