diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/entities/IncomingMessageList.java b/service/src/main/java/org/whispersystems/textsecuregcm/entities/IncomingMessageList.java
index 3f247e05f..e5f603463 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/entities/IncomingMessageList.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/entities/IncomingMessageList.java
@@ -49,6 +49,9 @@ public record IncomingMessageList(@NotNull
   @AssertTrue
   @Schema(hidden = true)
   public boolean isNotDuplicateRecipients() {
+    if (messages == null) {
+      return false;
+    }
     final boolean valid = messages.stream()
         .filter(Objects::nonNull)
         .map(IncomingMessage::destinationDeviceId).distinct().count() == messages.size();