diff --git a/sanitiser/_id.js b/sanitiser/_id.js
index 62860243..8f165f22 100644
--- a/sanitiser/_id.js
+++ b/sanitiser/_id.js
@@ -29,6 +29,11 @@ function sanitize( req ){
     req.clean.ids = [];
     params.ids = Array.isArray(params.id) ? params.id : [params.id];
     
+    // de-dupe
+    params.ids = params.ids.filter(function(item, pos) {
+      return params.ids.indexOf(item) == pos;
+    });
+
     for (var i=0; i<params.ids.length; i++) {
       var thisparam = params.ids[i];
     
diff --git a/test/unit/sanitiser/get.js b/test/unit/sanitiser/get.js
index 3de73397..8c7dd33d 100644
--- a/test/unit/sanitiser/get.js
+++ b/test/unit/sanitiser/get.js
@@ -102,6 +102,17 @@ module.exports.tests.sanitize_ids = function(test, common) {
   });
 };
 
+module.exports.tests.de_dupe = function(test, common) {
+  var expected = { ids: [ { id: '1', type: 'geoname' }, { id: '2', type: 'osmnode' } ] };
+  test('duplicate ids', function(t) {
+    sanitize( { id: ['geoname:1', 'osmnode:2', 'geoname:1'] }, function( err, clean ){
+      t.equal(err, undefined, 'no error' );
+      t.deepEqual(clean, expected, 'clean set correctly');
+      t.end();
+    });
+  });
+};
+
 module.exports.tests.invalid_params = function(test, common) {
   test('invalid params', function(t) {
     sanitize( undefined, function( err, clean ){