diff --git a/src/osgPlugins/iv/scanner.cpp b/src/osgPlugins/iv/scanner.cpp
index 8745f4c94..6f75ad309 100644
--- a/src/osgPlugins/iv/scanner.cpp
+++ b/src/osgPlugins/iv/scanner.cpp
@@ -23,7 +23,10 @@
 #ifdef __cplusplus
 
 #include <stdlib.h>
-#include <unistd.h>
+
+#if !defined(_MSC_VER)
+    #include <unistd.h>
+#endif
 
 /* Use prototypes in function declarations. */
 #define YY_USE_PROTOS