diff --git a/xpath.c b/xpath.c
index 881e936..ccf6c6c 100644
--- a/xpath.c
+++ b/xpath.c
@@ -10917,7 +10917,12 @@
         case XPATH_BOOLEAN:
 	    return(res->boolval);
         case XPATH_NUMBER:
+#ifdef WIN32
+	    return(((res->floatval == ctxt->context->proximityPosition) &&
+	           (!xmlXPathIsNaN(res->floatval)) /* MSC pbm Mark Vadoc !*/);
+#else
 	    return(res->floatval == ctxt->context->proximityPosition);
+#endif
         case XPATH_NODESET:
         case XPATH_XSLT_TREE:
 	    if (res->nodesetval == NULL)