diff --git a/src/conversions.cpp b/src/conversions.cpp
index 369f197a..88e30048 100644
--- a/src/conversions.cpp
+++ b/src/conversions.cpp
@@ -7,7 +7,8 @@
 //  producing this work.
 //
 // Revision History:
-// Mar 03 01  added: converters for [plain] char (Ralf W. Grosse-Kunstleve)
+// 04 Mar 01  std::complex<> fixes for MSVC (Dave Abrahams)
+// 03 Mar 01  added: converters for [plain] char (Ralf W. Grosse-Kunstleve)
 
 #include <boost/python/conversions.hpp>
 #include <typeinfo>
@@ -47,6 +48,19 @@ void handle_exception()
     }
 }
 
+namespace detail {
+
+  void expect_complex(PyObject* p)
+  {
+      if (!PyComplex_Check(p))
+      {
+          PyErr_SetString(PyExc_TypeError, "expected a complex number");
+          throw boost::python::argument_error();
+      }
+  }
+
+} // namespace boost::python::detail
+
 }} // namespace boost::python
 
 BOOST_PYTHON_BEGIN_CONVERSION_NAMESPACE