diff --git a/hash.c b/hash.c
index e3ce366f17..884868d019 100644
--- a/hash.c
+++ b/hash.c
@@ -18,6 +18,8 @@
 #include <fcntl.h>
 #ifdef _WIN32
 #include <io.h>
+#else
+#include <unistd.h>
 #endif
 #include "hash.h"
 #include <retro_miscellaneous.h>