diff --git a/src/mpdpp.cpp b/src/mpdpp.cpp
index f576e5ff..c79bbe6d 100644
--- a/src/mpdpp.cpp
+++ b/src/mpdpp.cpp
@@ -602,7 +602,7 @@ bool Connection::AddRandomTag(mpd_tag_type tag, size_t number, std::mt19937 &rng
 	return true;
 }
 
-bool Connection::AddRandomSongs(size_t number, std::string random_exclude_pattern, std::mt19937 &rng)
+bool Connection::AddRandomSongs(size_t number, const std::string &random_exclude_pattern, std::mt19937 &rng)
 {
 	prechecksNoCommandsList();
 	std::vector<std::string> files;
diff --git a/src/mpdpp.h b/src/mpdpp.h
index abd3666c..8b2138bf 100644
--- a/src/mpdpp.h
+++ b/src/mpdpp.h
@@ -547,7 +547,7 @@ struct Connection
 	int AddSong(const std::string &, int = -1); // returns id of added song
 	int AddSong(const Song &, int = -1); // returns id of added song
 	bool AddRandomTag(mpd_tag_type, size_t, std::mt19937 &rng);
-	bool AddRandomSongs(size_t number, std::string random_exclude_pattern, std::mt19937 &rng);
+	bool AddRandomSongs(size_t number, const std::string &random_exclude_pattern, std::mt19937 &rng);
 	void Add(const std::string &path);
 	void Delete(unsigned int pos);
 	void PlaylistDelete(const std::string &playlist, unsigned int pos);