diff --git a/prefs_interface.h b/prefs_interface.h
index a9b20a5..66fe8cb 100644
--- a/prefs_interface.h
+++ b/prefs_interface.h
@@ -16,6 +16,7 @@
 extern const char kPrefsUpdateCheckResponseHash[];
 extern const char kPrefsUpdateStateNextDataOffset[];
 extern const char kPrefsUpdateStateNextOperation[];
+extern const char kPrefsUpdateStateSHA256Context[];
 extern const char kPrefsUpdateStateSignedSHA256Context[];
 
 // The prefs interface allows access to a persistent preferences