diff --git a/test/explicit_operator_bool_noexcept.cpp b/test/explicit_operator_bool_noexcept.cpp
index d4b69eb..e913043 100644
--- a/test/explicit_operator_bool_noexcept.cpp
+++ b/test/explicit_operator_bool_noexcept.cpp
@@ -76,6 +76,11 @@ int main(int, char*[])
     BOOST_TEST(noexcept(static_cast< bool >(noexcept_val1)));
     BOOST_TEST(noexcept(static_cast< bool >(noexcept_val2)));
 
+    (void)val1;
+    (void)val2;
+    (void)noexcept_val1;
+    (void)noexcept_val2;
+
     return boost::report_errors();
 }