diff --git a/backend/src/api/analysis_api.py b/backend/src/api/analysis_api.py
index 2c6f604..1b3e924 100644
--- a/backend/src/api/analysis_api.py
+++ b/backend/src/api/analysis_api.py
@@ -174,7 +174,7 @@ class ConversationFlowEventEvidence(BaseModel):
     label: str
     src_label: str
     dst_label: str
-    packet_id: Optional[str] = None
+    packet_id: Optional[str | int] = None
 
 
 class ConversationFlowDetailResponse(BaseModel):