diff --git a/FirebaseRemoteConfig/Sources/RCNConfigConstants.h b/FirebaseRemoteConfig/Sources/RCNConfigConstants.h
index db0e0213ae1..e3cd99088a9 100644
--- a/FirebaseRemoteConfig/Sources/RCNConfigConstants.h
+++ b/FirebaseRemoteConfig/Sources/RCNConfigConstants.h
@@ -37,6 +37,8 @@ static NSString *const RCNFetchResponseKeyEntries = @"entries";
 static NSString *const RCNFetchResponseKeyExperimentDescriptions = @"experimentDescriptions";
 /// Key that includes data for Personalization metadata.
 static NSString *const RCNFetchResponseKeyPersonalizationMetadata = @"personalizationMetadata";
+/// Key that includes data for Rollout metadata.
+static NSString *const RCNFetchResponseKeyRolloutMetadata = @"rolloutMetadata";
 /// Error key.
 static NSString *const RCNFetchResponseKeyError = @"error";
 /// Error code.