diff --git a/packages/firebase_auth/firebase_auth/ios/Classes/PigeonParser.m b/packages/firebase_auth/firebase_auth/ios/Classes/PigeonParser.m
index 61e600df759e..63f64aab88f1 100644
--- a/packages/firebase_auth/firebase_auth/ios/Classes/PigeonParser.m
+++ b/packages/firebase_auth/firebase_auth/ios/Classes/PigeonParser.m
@@ -179,7 +179,7 @@ + (PigeonIdTokenResult *)parseIdTokenResult:(FIRAuthTokenResult *)tokenResult {
                          signInSecondFactor:tokenResult.signInSecondFactor];
 }
 
-+ (NSArray *)getManualList:(nonnull PigeonUserDetails *)userDetails {
++ (NSArray *_Nonnull)getManualList:(nonnull PigeonUserDetails *)userDetails {
   NSMutableArray *output = [NSMutableArray array];
 
   id userInfoList = [[userDetails userInfo] toList];
diff --git a/packages/firebase_auth/firebase_auth/ios/Classes/Private/PigeonParser.h b/packages/firebase_auth/firebase_auth/ios/Classes/Private/PigeonParser.h
index e0f45472dd1a..02f5e0d84db6 100644
--- a/packages/firebase_auth/firebase_auth/ios/Classes/Private/PigeonParser.h
+++ b/packages/firebase_auth/firebase_auth/ios/Classes/Private/PigeonParser.h
@@ -10,7 +10,7 @@
 
 @interface PigeonParser : NSObject
 
-+ (NSArray *)getManualList:(nonnull PigeonUserDetails *)userDetails;
++ (NSArray *_Nonnull)getManualList:(nonnull PigeonUserDetails *)userDetails;
 + (PigeonUserCredential *_Nullable)
     getPigeonUserCredentialFromAuthResult:(nonnull FIRAuthDataResult *)authResult
                         authorizationCode:(nullable NSString *)authorizationCode;