diff --git a/Makefile b/Makefile
index c692e90..a572fef 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ makechat:
 	GO111MODULE=off go run make_chat.go
 
 parselog:
-	GO111MODULE=off go run parse_protobuf_log.go
+	GO111MODULE=off go run parse_protobuf_log.go log/sample.text
 
 goimports:
 	goimports -w *.go
diff --git a/parse_protobuf_log.go b/parse_protobuf_log.go
index b784ee5..1131ac3 100644
--- a/parse_protobuf_log.go
+++ b/parse_protobuf_log.go
@@ -8,7 +8,9 @@ import (
 )
 
 func main() {
-	data, _ := os.ReadFile("log/sample.text")
+	filename := os.Args[1]
+	// data, _ := os.ReadFile("log/sample.text")
+	data, _ := os.ReadFile(filename)
 	log.Info("trying unmarshal len(data) =", len(data))
 	pb, err := chatpb.UnmarshalChatsTEXT(data)
 	if err != nil {