diff --git a/metadata-ingestion/src/datahub/emitter/rest_emitter.py b/metadata-ingestion/src/datahub/emitter/rest_emitter.py
index 74b8ade7da445b..7271f784bf881e 100644
--- a/metadata-ingestion/src/datahub/emitter/rest_emitter.py
+++ b/metadata-ingestion/src/datahub/emitter/rest_emitter.py
@@ -374,7 +374,7 @@ def emit_mcps(
             # the size when chunking, and again for the actual request.
             payload_dict: dict = {"proposals": mcp_obj_chunk}
             if async_flag is not None:
-                payload_dict["async"] = True if async_flag else False
+                payload_dict["async"] = "true" if async_flag else "false"
 
             payload = json.dumps(payload_dict)
             self._emit_generic(url, payload)