diff --git a/lib/protoparser/promremotewrite/stream/streamparser.go b/lib/protoparser/promremotewrite/stream/streamparser.go
index 347a63217..546c8c0f2 100644
--- a/lib/protoparser/promremotewrite/stream/streamparser.go
+++ b/lib/protoparser/promremotewrite/stream/streamparser.go
@@ -110,7 +110,7 @@ func (ctx *pushCtx) Read() error {
 	}
 	if reqLen > int64(maxInsertRequestSize.N) {
 		readErrors.Inc()
-		return fmt.Errorf("too big packed request; mustn't exceed -maxInsertRequestSize=%d bytes", maxInsertRequestSize.N)
+		return fmt.Errorf("too big packed request; mustn't exceed -maxInsertRequestSize=%d bytes; got %d bytes", maxInsertRequestSize.N, reqLen)
 	}
 	return nil
 }