diff --git a/api/api_full.go b/api/api_full.go
index d5e97d3a6..1edebc4a6 100644
--- a/api/api_full.go
+++ b/api/api_full.go
@@ -2,6 +2,7 @@ package api
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"time"
 
@@ -785,6 +786,22 @@ type StartDealParams struct {
 	VerifiedDeal       bool
 }
 
+func (s *StartDealParams) UnmarshalJSON(raw []byte) (err error) {
+	type sdpAlias StartDealParams
+
+	sdp := sdpAlias{
+		FastRetrieval: true,
+	}
+
+	if err := json.Unmarshal(raw, &sdp); err != nil {
+		return err
+	}
+
+	*s = StartDealParams(sdp)
+
+	return nil
+}
+
 type IpldObject struct {
 	Cid cid.Cid
 	Obj interface{}