diff --git a/libs/binder/ndk/include_cpp/android/binder_to_string.h b/libs/binder/ndk/include_cpp/android/binder_to_string.h
index 27fdcdb..e3ead11 100644
--- a/libs/binder/ndk/include_cpp/android/binder_to_string.h
+++ b/libs/binder/ndk/include_cpp/android/binder_to_string.h
@@ -166,6 +166,11 @@
     enum { value = decltype(_test<_T>(0))::value };
 };
 
+template <typename _T>
+struct TypeDependentFalse {
+    enum { value = false };
+};
+
 }  // namespace details
 
 template <typename _T>
@@ -225,7 +230,7 @@
         out << "]";
         return out.str();
     } else {
-        return "{no toString() implemented}";
+        static_assert(details::TypeDependentFalse<_T>::value, "no toString implemented, huh?");
     }
 }