diff --git a/test/hash_reference_values.cpp b/test/hash_reference_values.cpp
index 5a0289c..842bfd3 100644
--- a/test/hash_reference_values.cpp
+++ b/test/hash_reference_values.cpp
@@ -126,6 +126,7 @@ int main()
 
 #if defined(BOOST_GCC) && BOOST_GCC < 100000
 
+    // This looks like some sort of miscompilation
     BOOST_TEST_EQ( hv((uint128)-1), 18446744073709551615ULL );
 
 #else