diff --git a/fetch/wire_types.go b/fetch/wire_types.go
index d27455472a..70e8b1de95 100644
--- a/fetch/wire_types.go
+++ b/fetch/wire_types.go
@@ -22,7 +22,7 @@ type RequestMessage struct {
 // ResponseMessage is sent to the node as a response.
 type ResponseMessage struct {
 	Hash types.Hash32
-	Data []byte `scale:"max=20971520"` // limit to 20 MiB
+	Data []byte `scale:"max=41943040"` // limit to 40 MiB
 }
 
 // RequestBatch is a batch of requests and a hash of all requests as ID.
diff --git a/fetch/wire_types_scale.go b/fetch/wire_types_scale.go
index 939fe94026..6e81e111d8 100644
--- a/fetch/wire_types_scale.go
+++ b/fetch/wire_types_scale.go
@@ -55,7 +55,7 @@ func (t *ResponseMessage) EncodeScale(enc *scale.Encoder) (total int, err error)
 		total += n
 	}
 	{
-		n, err := scale.EncodeByteSliceWithLimit(enc, t.Data, 20971520)
+		n, err := scale.EncodeByteSliceWithLimit(enc, t.Data, 41943040)
 		if err != nil {
 			return total, err
 		}
@@ -73,7 +73,7 @@ func (t *ResponseMessage) DecodeScale(dec *scale.Decoder) (total int, err error)
 		total += n
 	}
 	{
-		field, n, err := scale.DecodeByteSliceWithLimit(dec, 20971520)
+		field, n, err := scale.DecodeByteSliceWithLimit(dec, 41943040)
 		if err != nil {
 			return total, err
 		}