diff --git a/src/main/java/net/teumteum/alert/infra/FcmAlertPublisher.java b/src/main/java/net/teumteum/alert/infra/FcmAlertPublisher.java
index c7bd902..6853283 100644
--- a/src/main/java/net/teumteum/alert/infra/FcmAlertPublisher.java
+++ b/src/main/java/net/teumteum/alert/infra/FcmAlertPublisher.java
@@ -42,7 +42,8 @@ private void publishWithRetry(int currentRetryCount, Message message, @Nullable
         if (MAX_RETRY_COUNT == currentRetryCount) {
             return;
         }
-        if (errorCode == ErrorCode.INTERNAL
+        if (errorCode == null
+            || errorCode == ErrorCode.INTERNAL
             || errorCode == ErrorCode.CONFLICT
             || errorCode == ErrorCode.UNKNOWN
             || errorCode == ErrorCode.DATA_LOSS) {