diff --git a/lib/dao.js b/lib/dao.js
index c018fe57..e7d08012 100644
--- a/lib/dao.js
+++ b/lib/dao.js
@@ -296,19 +296,19 @@ DataAccessObject.findOrCreate = function findOrCreate(query, data, callback) {
 DataAccessObject.exists = function exists(id, cb) {
     if (stillConnecting(this.dataSource, this, arguments)) return;
 
-    if (id) {
+    if (id !== undefined && id !== null && id !== '') {
         this.dataSource.connector.exists(this.modelName, id, cb);
     } else {
-        cb(new Error('Model::exists requires positive id argument'));
+        cb(new Error('Model::exists requires the id argument'));
     }
 };
 
 // exists ~ remoting attributes
 setRemoting(DataAccessObject.exists, {
     description: 'Check whether a model instance exists in the data source',
-    accepts: {arg: 'id', type: 'any', description: 'Model id'},
+    accepts: {arg: 'id', type: 'any', description: 'Model id', required: true},
     returns: {arg: 'exists', type: 'any'},
-    http: {verb: 'get', path: '/exists'}
+    http: {verb: 'get', path: '/:id/exists'}
 });
 
 /**
@@ -336,7 +336,7 @@ DataAccessObject.findById = function find(id, cb) {
 // find ~ remoting attributes
 setRemoting(DataAccessObject.findById, {
     description: 'Find a model instance by id from the data source',
-    accepts: {arg: 'id', type: 'any', description: 'Model id'},
+    accepts: {arg: 'id', type: 'any', description: 'Model id', required: true},
     returns: {arg: 'data', type: 'any', root: true},
     http: {verb: 'get', path: '/:id'}
 });
@@ -530,7 +530,7 @@ DataAccessObject.deleteById =
 // deleteById ~ remoting attributes
 setRemoting(DataAccessObject.deleteById, {
     description: 'Delete a model instance by id from the data source',
-    accepts: {arg: 'id', type: 'any', description: 'Model id'},
+    accepts: {arg: 'id', type: 'any', description: 'Model id', required: true},
     http: {verb: 'del', path: '/:id'}
 });