diff --git a/Ext4Crypt.h b/Ext4Crypt.h
index 301639d..68e0fb2 100644
--- a/Ext4Crypt.h
+++ b/Ext4Crypt.h
@@ -1,3 +1,4 @@
+#include <stddef.h>
 #include <sys/cdefs.h>
 
 __BEGIN_DECLS
@@ -12,5 +13,9 @@
 int e4crypt_get_password_type(const char* path);
 const char* e4crypt_get_password(const char* path);
 int e4crypt_restart(const char* path);
+int e4crypt_get_field(const char* path, const char* fieldname,
+                      char* value, size_t len);
+int e4crypt_set_field(const char* path, const char* fieldname,
+                      const char* value);
 
 __END_DECLS