diff --git a/common/constants.cc b/common/constants.cc
index b15c3f4..6b1d416 100644
--- a/common/constants.cc
+++ b/common/constants.cc
@@ -45,6 +45,7 @@
 const char kPrefsLastActivePingDay[] = "last-active-ping-day";
 const char kPrefsLastRollCallPingDay[] = "last-roll-call-ping-day";
 const char kPrefsManifestMetadataSize[] = "manifest-metadata-size";
+const char kPrefsManifestSignatureSize[] = "manifest-signature-size";
 const char kPrefsMetricsAttemptLastReportingTime[] =
     "metrics-attempt-last-reporting-time";
 const char kPrefsMetricsCheckLastReportingTime[] =
diff --git a/common/constants.h b/common/constants.h
index 62f61ce..f9a43c6 100644
--- a/common/constants.h
+++ b/common/constants.h
@@ -50,6 +50,7 @@
 extern const char kPrefsLastActivePingDay[];
 extern const char kPrefsLastRollCallPingDay[];
 extern const char kPrefsManifestMetadataSize[];
+extern const char kPrefsManifestSignatureSize[];
 extern const char kPrefsMetricsAttemptLastReportingTime[];
 extern const char kPrefsMetricsCheckLastReportingTime[];
 extern const char kPrefsNumReboots[];