diff --git a/src/test-meta.cc b/src/test-meta.cc
index 0b6e02c26..9436b9038 100644
--- a/src/test-meta.cc
+++ b/src/test-meta.cc
@@ -29,6 +29,8 @@
 
 #include <type_traits>
 
+template <typename T> struct U { typedef T type; };
+
 int
 main (int argc, char **argv)
 {
@@ -122,6 +124,9 @@ main (int argc, char **argv)
   static_assert (hb_is_trivial (X), "");
   static_assert (hb_is_trivial (Y), "");
 
+  static_assert (hb_is_signed (hb_unwrap_type (U<U<U<int>>>)), "");
+  static_assert (hb_is_unsigned (hb_unwrap_type (U<U<U<U<unsigned>>>>)), "");
+
   /* TODO Add more meaningful tests. */
 
   return 0;