diff --git a/Source/cmStandardIncludes.h b/Source/cmStandardIncludes.h
index 468a589..e212616 100644
--- a/Source/cmStandardIncludes.h
+++ b/Source/cmStandardIncludes.h
@@ -54,6 +54,8 @@
 
 #if defined( _MSC_VER )
 typedef unsigned short mode_t;
+#else
+# include <sys/types.h>
 #endif
 
 // use this class to shrink the size of symbols in .o files