diff --git a/constants.cc b/constants.cc
index 11d5901..767dc47 100644
--- a/constants.cc
+++ b/constants.cc
@@ -55,6 +55,7 @@
     "update-over-cellular-permission";
 const char kPrefsUpdateServerCertificate[] = "update-server-cert";
 const char kPrefsUpdateStateNextDataOffset[] = "update-state-next-data-offset";
+const char kPrefsUpdateStateNextDataLength[] = "update-state-next-data-length";
 const char kPrefsUpdateStateNextOperation[] = "update-state-next-operation";
 const char kPrefsUpdateStateSHA256Context[] = "update-state-sha-256-context";
 const char kPrefsUpdateStateSignatureBlob[] = "update-state-signature-blob";