diff --git a/encoding/protobuf/util.go b/encoding/protobuf/util.go
index 38521ab..53b3b43 100644
--- a/encoding/protobuf/util.go
+++ b/encoding/protobuf/util.go
@@ -66,7 +66,8 @@
 		cg.Position = 10
 	}
 	for _, s := range c.Lines {
-		cg.List = append(cg.List, &ast.Comment{Text: "// " + s})
+		s = strings.TrimRight(s, " ")
+		cg.List = append(cg.List, &ast.Comment{Text: "//" + s})
 	}
 	return cg
 }