diff --git a/constants.h b/constants.h
index 076aeae..7b3dca9 100644
--- a/constants.h
+++ b/constants.h
@@ -46,6 +46,9 @@
 extern const char kPrefsResumedUpdateFailures[];
 extern const char kPrefsRollbackVersion[];
 extern const char kPrefsSystemUpdatedMarker[];
+extern const char kPrefsTargetVersionAttempt[];
+extern const char kPrefsTargetVersionInstalledFrom[];
+extern const char kPrefsTargetVersionUniqueId[];
 extern const char kPrefsTotalBytesDownloaded[];
 extern const char kPrefsUpdateCheckCount[];
 extern const char kPrefsUpdateCheckResponseHash[];