diff --git a/src/json-uri.cpp b/src/json-uri.cpp
index 2809fa1..6ff1c16 100644
--- a/src/json-uri.cpp
+++ b/src/json-uri.cpp
@@ -44,7 +44,7 @@ void json_uri::update(const std::string &uri)
 
 	auto location = uri.substr(0, pointer_separator);
 
-	if (location.size()) {          // a location part has been found
+	if (location.size()) { // a location part has been found
 
 		// if it is an URN take it as it is
 		if (location.find("urn:") == 0) {
@@ -99,7 +99,7 @@ void json_uri::update(const std::string &uri)
 		identifier_ = pointer;
 }
 
-const std::string json_uri::location() const
+std::string json_uri::location() const
 {
 	if (urn_.size())
 		return urn_;
diff --git a/src/nlohmann/json-schema.hpp b/src/nlohmann/json-schema.hpp
index 518a0c7..2d18411 100644
--- a/src/nlohmann/json-schema.hpp
+++ b/src/nlohmann/json-schema.hpp
@@ -71,14 +71,14 @@ public:
 		update(uri);
 	}
 
-	const std::string scheme() const { return scheme_; }
-	const std::string authority() const { return authority_; }
-	const std::string path() const { return path_; }
+	const std::string &scheme() const { return scheme_; }
+	const std::string &authority() const { return authority_; }
+	const std::string &path() const { return path_; }
 
-	const json::json_pointer pointer() const { return pointer_; }
-	const std::string identifier() const { return identifier_; }
+	const json::json_pointer &pointer() const { return pointer_; }
+	const std::string &identifier() const { return identifier_; }
 
-	const std::string fragment() const
+	std::string fragment() const
 	{
 		if (identifier_ == "")
 			return pointer_;
@@ -86,8 +86,8 @@ public:
 			return identifier_;
 	}
 
-	const std::string url() const { return location(); }
-	const std::string location() const;
+	std::string url() const { return location(); }
+	std::string location() const;
 
 	static std::string escape(const std::string &);