diff --git a/mev_inspect/schemas/classified_traces.py b/mev_inspect/schemas/classified_traces.py
index 8a51214..0a48687 100644
--- a/mev_inspect/schemas/classified_traces.py
+++ b/mev_inspect/schemas/classified_traces.py
@@ -55,6 +55,7 @@ class ClassifiedTraceStrict(BaseModel):
     trace_type: TraceType
     trace_address: List[int]
     classification: Classification
+    error: Optional[str]
 
     class Config:
         json_encoders = {