diff --git a/src/hash.c b/src/hash.c
index e6fc8d1..686ab22 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -23,6 +23,8 @@
 # include <config.h>
 #endif/*HAVE_CONFIG_H*/
 
+#include <sys/types.h>
+
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>