diff --git a/src/tests/turtle_test/log_with_conversions_test.cpp b/src/tests/turtle_test/log_with_conversions_test.cpp
index 1e61116..50ca6d6 100644
--- a/src/tests/turtle_test/log_with_conversions_test.cpp
+++ b/src/tests/turtle_test/log_with_conversions_test.cpp
@@ -418,8 +418,8 @@ namespace
 
 BOOST_AUTO_TEST_CASE( callable_builtin_yields_an_interrogation_mark_when_serialized_with_conversions )
 {
-    BOOST_CHECK_EQUAL( "?", to_string_2( callable_builtin ) );
-    BOOST_CHECK_EQUAL( "?", to_string_2( &callable_builtin ) );
+    BOOST_CHECK_EQUAL( "?", to_string( callable_builtin ) );
+    BOOST_CHECK_EQUAL( "?", to_string( &callable_builtin ) );
 }
 
 namespace