diff --git a/include/mapnik/font_set.hpp b/include/mapnik/font_set.hpp
index 19f0f8119..781e3830d 100644
--- a/include/mapnik/font_set.hpp
+++ b/include/mapnik/font_set.hpp
@@ -46,7 +46,7 @@ public:
     std::size_t size() const;
     void set_name(std::string const& name);
     std::string const& get_name() const;
-    void add_face_name(std::string const& face_name);
+    void add_face_name(std::string face_name);
     std::vector<std::string> const& get_face_names() const;
 
 private:
diff --git a/src/font_set.cpp b/src/font_set.cpp
index 4ef5274eb..da78073c7 100644
--- a/src/font_set.cpp
+++ b/src/font_set.cpp
@@ -62,7 +62,7 @@ std::size_t font_set::size() const
     return face_names_.size();
 }
 
-void font_set::add_face_name(std::string const& face_name)
+void font_set::add_face_name(std::string face_name)
 {
     face_names_.push_back(std::move(face_name));
 }