diff --git a/langfuse/_client/client.py b/langfuse/_client/client.py
index a8781c9b9..9beed5f67 100644
--- a/langfuse/_client/client.py
+++ b/langfuse/_client/client.py
@@ -1818,7 +1818,7 @@ def create_score(
         try:
             new_body = ScoreBody(
                 id=score_id,
-                session_id=session_id,
+                sessionId=session_id,
                 datasetRunId=dataset_run_id,
                 traceId=trace_id,
                 observationId=observation_id,