diff --git a/include/server/api/url_parser.hpp b/include/server/api/url_parser.hpp
index 0bac20f30..5fcca36d1 100644
--- a/include/server/api/url_parser.hpp
+++ b/include/server/api/url_parser.hpp
@@ -15,8 +15,8 @@ namespace api
 {
 
 // Starts parsing and iter and modifies it until iter == end or parsing failed
-boost::optional<ParsedURL> parseURL(std::string::iterator &iter, std::string::iterator end);
-// copy on purpose because we need mutability
+boost::optional<ParsedURL> parseURL(std::string::iterator &iter, const std::string::iterator end);
+
 inline boost::optional<ParsedURL> parseURL(std::string url_string)
 {
     auto iter = url_string.begin();
diff --git a/src/server/api/url_parser.cpp b/src/server/api/url_parser.cpp
index 661b1f67f..a95c4a1bc 100644
--- a/src/server/api/url_parser.cpp
+++ b/src/server/api/url_parser.cpp
@@ -69,7 +69,7 @@ struct URLGrammar : boost::spirit::qi::grammar<Iterator>
 };
 }
 
-boost::optional<ParsedURL> parseURL(std::string::iterator &iter, std::string::iterator end)
+boost::optional<ParsedURL> parseURL(std::string::iterator &iter, const std::string::iterator end)
 {
     boost::optional<ParsedURL> parsed_url;