diff --git a/Firebase/Messaging/FIRMessagingDataMessageManager.h b/Firebase/Messaging/FIRMessagingDataMessageManager.h
index 8eaecc120d2..cf8df74e320 100644
--- a/Firebase/Messaging/FIRMessagingDataMessageManager.h
+++ b/Firebase/Messaging/FIRMessagingDataMessageManager.h
@@ -46,7 +46,7 @@
  *  @param messageID The messageId passed in by the app to track this particular message.
  *  @param error     The error in case FIRMessaging cannot send the message upstream.
  */
-- (void)willSendDataMessageWithID:(nonnull NSString *)messageID error:(nullable NSError *)error;
+- (void)willSendDataMessageWithID:(nullable NSString *)messageID error:(nullable NSError *)error;
 
 /**
  *  Notify the app that FIRMessaging did successfully send it's message via the MCS
@@ -86,7 +86,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark - Receive
 
-- (NSDictionary *)processPacket:(GtalkDataMessageStanza *)packet;
+- (nullable NSDictionary *)processPacket:(GtalkDataMessageStanza *)packet;
 - (void)didReceiveParsedMessage:(NSDictionary *)message;
 
 #pragma mark - Send
diff --git a/Firebase/Messaging/FIRMessagingDataMessageManager.m b/Firebase/Messaging/FIRMessagingDataMessageManager.m
index 58dae87c670..b62763a105e 100644
--- a/Firebase/Messaging/FIRMessagingDataMessageManager.m
+++ b/Firebase/Messaging/FIRMessagingDataMessageManager.m
@@ -112,7 +112,7 @@ - (void)refreshDelayedMessages {
                               }];
 }
 
-- (NSDictionary *)processPacket:(GtalkDataMessageStanza *)dataMessage {
+- (nullable NSDictionary *)processPacket:(GtalkDataMessageStanza *)dataMessage {
   NSString *category = dataMessage.category;
   NSString *from = dataMessage.from;
   if ([kFCMMessageCategory isEqualToString:category] ||
diff --git a/Firebase/Messaging/FIRMessagingRmq2PersistentStore.m b/Firebase/Messaging/FIRMessagingRmq2PersistentStore.m
index 76716e66e34..dc6e6c9c9dd 100644
--- a/Firebase/Messaging/FIRMessagingRmq2PersistentStore.m
+++ b/Firebase/Messaging/FIRMessagingRmq2PersistentStore.m
@@ -286,7 +286,6 @@ - (void)openDatabase:(NSString *)dbName {
                               @"%@",
                               errorMessage);
       NSAssert(NO, errorMessage);
-      didOpenDatabase = NO;
       return;
     }
     [self createTableWithName:kTableOutgoingRmqMessages