diff --git a/file.h b/file.h
index d4a2e19d3a..5d4add33a1 100644
--- a/file.h
+++ b/file.h
@@ -22,6 +22,7 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <stddef.h>
+#include <sys/types.h>
 
 ssize_t read_file(FILE *file, void **buf);