diff --git a/src/py_utils.cc b/src/py_utils.cc
index 3e788442..c2177c20 100644
--- a/src/py_utils.cc
+++ b/src/py_utils.cc
@@ -74,11 +74,13 @@ typedef register_python_conversion<bool, bool_to_python, bool_from_python>
   bool_python_conversion;
 
 
+#if defined(STRING_VERIFY_ON)
+
 struct string_to_python
 {
-  static PyObject* convert(const string& str)
+  static PyObject* convert(const ledger::string& str)
   {
-    return incref(object(*boost::polymorphic_downcast<const std::string *>(&str)).ptr());
+    return incref(object(static_cast<const std::string&>(str)).ptr());
   }
 };
 
@@ -95,15 +97,17 @@ struct string_from_python
     const char* value = PyString_AsString(obj_ptr);
     if (value == 0) throw_error_already_set();
     void* storage =
-      reinterpret_cast<converter::rvalue_from_python_storage<string> *>(data)->storage.bytes;
-    new (storage) string(value);
+      reinterpret_cast<converter::rvalue_from_python_storage<ledger::string> *>(data)->storage.bytes;
+    new (storage) ledger::string(value);
     data->convertible = storage;
   }
 };
 
-typedef register_python_conversion<string, string_to_python, string_from_python>
+typedef register_python_conversion<ledger::string, string_to_python, string_from_python>
   string_python_conversion;
 
+#endif // STRING_VERIFY_ON
+
 
 struct istream_to_python
 {
@@ -209,7 +213,9 @@ void export_utils()
     ;
 
   bool_python_conversion();
+#if defined(STRING_VERIFY_ON)
   string_python_conversion();
+#endif
   istream_python_conversion();
   ostream_python_conversion();
 }
diff --git a/src/utils.cc b/src/utils.cc
index c68737dc..2f2899fb 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -407,6 +407,8 @@ void report_memory(std::ostream& out, bool report_all)
 }
 
 
+#if defined(STRING_VERIFY_ON)
+
 string::string() : std::string() {
   TRACE_CTOR(string, "");
 }
@@ -443,6 +445,8 @@ string::~string() throw() {
   TRACE_DTOR(string);
 }
 
+#endif // STRING_VERIFY_ON
+
 } // namespace ledger
 
 #endif // VERIFY_ON
diff --git a/src/utils.h b/src/utils.h
index c3d3cf24..a8784a66 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -62,6 +62,10 @@
 #define TIMERS_ON   1
 #endif
 
+#if defined(VERIFY_ON)
+//#define STRING_VERIFY_ON 1
+#endif
+
 /*@}*/
 
 /**
@@ -72,7 +76,7 @@
 namespace ledger {
   using namespace boost;
 
-#if defined(VERIFY_ON)
+#if defined(STRING_VERIFY_ON)
   class string;
 #else
   typedef std::string string;
@@ -158,6 +162,8 @@ void trace_dtor_func(void * ptr, const char * cls_name, std::size_t cls_size);
 
 void report_memory(std::ostream& out, bool report_all = false);
 
+#if defined(STRING_VERIFY_ON)
+
 /**
  * @brief Brief
  *
@@ -236,6 +242,8 @@ inline bool operator!=(const char* __lhs, const string& __rhs)
 inline bool operator!=(const string& __lhs, const char* __rhs)
 { return __lhs.compare(__rhs) != 0; }
 
+#endif // STRING_VERIFY_ON
+
 } // namespace ledger
 
 #else // ! VERIFY_ON