diff --git a/src/generic/util/dirent_safe.h b/src/generic/util/dirent_safe.h

index 5c83c2c..ab42e7f 100644

--- a/src/generic/util/dirent_safe.h

+++ b/src/generic/util/dirent_safe.h

@@ -20,6 +20,7 @@

 #ifndef DIRENT_SAFE_H

 #define DIRENT_SAFE_H

+#include <stddef.h>

 #include <dirent.h>

 /** \brief A version of dirent that's safe to use with readdir_r