--- a/ThirdParty/ioss/vtkioss/Ioss_FileInfo.C.orig
+++ b/ThirdParty/ioss/vtkioss/Ioss_FileInfo.C
@@ -26,7 +26,7 @@
 #define S_ISDIR(m) (((m)&_S_IFMT) == _S_IFDIR)
 #endif
 #else
-#include <sys/unistd.h>
+#include <unistd.h>
 #endif
 
 #ifdef SEACAS_HAVE_MPI