diff --git a/src/dispatch/signal/flows.py b/src/dispatch/signal/flows.py
index 4891abf2dfad..141808840526 100644
--- a/src/dispatch/signal/flows.py
+++ b/src/dispatch/signal/flows.py
@@ -81,9 +81,9 @@ def signal_instance_create_flow(
         db_session=db_session,
         signal_instance=signal_instance,
     ):
-        # If the signal was deduplicated, we can assume a case exists,
-        # and we need to update the corresponding signal message
-        if _should_update_signal_message(signal_instance):
+        # If a case exists and the signal was deduplicated,
+        # we need to update the corresponding signal message
+        if signal_instance.case_id and _should_update_signal_message(signal_instance):
             update_signal_message(
                 db_session=db_session,
                 signal_instance=signal_instance,