diff --git a/include/ncconfigure.h b/include/ncconfigure.h
index 2c5b2c8..d397790 100644
--- a/include/ncconfigure.h
+++ b/include/ncconfigure.h
@@ -25,20 +25,20 @@ missing functions should be
 defined and missing types defined.
 */
 
-#ifndef HAVE_STRDUP
+#ifndef strdup
 extern char* strdup(const char*);
 #endif
 
 /* handle null arguments */
 #ifndef nulldup
-#ifdef HAVE_STRDUP
+#ifdef strdup
 #define nulldup(s) ((s)==NULL?NULL:strdup(s))
 #else
 char *nulldup(const char* s);
 #endif
 #endif
 
-#ifdef _MSC_VER
+#ifdef _WIN32
 #ifndef HAVE_SSIZE_T
 #include <basetsd.h>
 typedef SSIZE_T ssize_t;