diff --git a/uri.cpp b/uri.cpp
index c52c5b13..43fc4a50 100644
--- a/uri.cpp
+++ b/uri.cpp
@@ -211,14 +211,14 @@ void uri::clear_fragment ()
 
 
 ///////////////////////////////////////////////////////////////////////////////
-std::map<std::string, std::string>
-cruft::query_to_map (std::string_view val)
+std::vector<std::pair<std::string, std::string>>
+cruft::query_to_vector (std::string_view val)
 {
-    std::map<std::string, std::string> res;
+    std::vector<std::pair<std::string, std::string>> res;
 
     for (auto const tok: cruft::tokeniser (val, '&')) {
         auto const &[k, v] = cruft::split_on (tok, '=');
-        res.emplace (
+        res.emplace_back (
             std::string (k.begin (), k.size ()),
             std::string (v.begin (), v.size ())
         );
@@ -230,7 +230,7 @@ cruft::query_to_map (std::string_view val)
 
 //-----------------------------------------------------------------------------
 std::string
-cruft::map_to_query (std::map<std::string, std::string> const &val)
+cruft::vector_to_query (std::vector<std::pair<std::string, std::string>> const &val)
 {
     // Test for empty up front so that we can simplify the string
     // concatenation below.
diff --git a/uri.hpp b/uri.hpp
index 83ee9769..c84a1b2f 100644
--- a/uri.hpp
+++ b/uri.hpp
@@ -114,8 +114,18 @@ namespace cruft {
         std::string m_value;
     };
 
-    std::map<std::string, std::string> query_to_map (std::string_view);
-    std::string map_to_query (std::map<std::string, std::string> const&);
+    /// Break a query string into a sequence of key-value pairs.
+    /// Duplicates are possible.
+    /// vector is used to that order can be preserved
+    /// The is the inverse of vector_to_query
+    std::vector<std::pair<std::string, std::string>>
+    query_to_vector (std::string_view);
+
+    /// Convert a sequence of key-value pairs into a query string
+    /// All pairs, including duplicates, are serialised in the provided order.
+    /// This is the inverse of query_to_vector
+    std::string
+    vector_to_query (std::vector<std::pair<std::string, std::string>> const&);
 
     bool operator== (uri const&, uri const&) noexcept;