@@ -22,11 +22,13 @@
 #include <stdlib.h>	/* include any libc header to get the libc defines */
 #ifdef __GLIBC__
 # undef __USE_XOPEN
 #endif
 
-#include <unistd.h>
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
 
 #include "platform.h"
 
 #ifdef OF_MACOS
 # include <sys/sysctl.h>