diff --git a/src/hash/helper.c b/src/hash/helper.c
index d9362d3..352f978 100644
--- a/src/hash/helper.c
+++ b/src/hash/helper.c
@@ -19,6 +19,9 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#ifdef _WIN32
+#include <io.h>
+#endif
 
 #include <hashinc>