diff --git a/src/mango/test/18-json-sort.py b/src/mango/test/18-json-sort.py
deleted file mode 100644
index ebc3b024e06..00000000000
--- a/src/mango/test/18-json-sort.py
+++ /dev/null
@@ -1,122 +0,0 @@
-# Licensed under the Apache License, Version 2.0 (the "License"); you may not
-# use this file except in compliance with the License. You may obtain a copy of
-# the License at
-#
-#   http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations under
-# the License.
-
-import mango
-import copy
-import unittest
-
-DOCS = [
-    {"_id": "1", "name": "Jimi", "age": 10, "cars": 1},
-    {"_id": "2", "name": "Eddie", "age": 20, "cars": 1},
-    {"_id": "3", "name": "Jane", "age": 30, "cars": 2},
-    {"_id": "4", "name": "Mary", "age": 40, "cars": 2},
-    {"_id": "5", "name": "Sam", "age": 50, "cars": 3},
-]
-
-
-class JSONIndexSortOptimisations(mango.DbPerClass):
-    def setUp(self):
-        super().setUp(db_per_test=True)
-        self.db.save_docs(copy.deepcopy(DOCS))
-
-    def test_works_for_basic_case(self):
-        self.db.create_index(["cars", "age"], name="cars-age")
-        selector = {"cars": "2", "age": {"$gt": 10}}
-        explain = self.db.find(selector, sort=["age"], explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age")
-        self.assertEqual(explain["mrargs"]["direction"], "fwd")
-
-    def test_works_for_all_fields_specified(self):
-        self.db.create_index(["cars", "age"], name="cars-age")
-        selector = {"cars": "2", "age": {"$gt": 10}}
-        explain = self.db.find(selector, sort=["cars", "age"], explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age")
-
-    def test_works_for_no_sort_fields_specified(self):
-        self.db.create_index(["cars", "age"], name="cars-age")
-        selector = {"cars": {"$gt": 10}, "age": {"$gt": 10}}
-        explain = self.db.find(selector, explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age")
-
-    def test_works_for_opp_dir_sort(self):
-        self.db.create_index(["cars", "age"], name="cars-age")
-        selector = {"cars": "2", "age": {"$gt": 10}}
-        explain = self.db.find(selector, sort=[{"age": "desc"}], explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age")
-        self.assertEqual(explain["mrargs"]["direction"], "rev")
-
-    def test_not_work_for_non_constant_field(self):
-        self.db.create_index(["cars", "age"], name="cars-age")
-        selector = {"cars": {"$gt": 10}, "age": {"$gt": 10}}
-        try:
-            self.db.find(selector, sort=["age"])
-            raise Exception("Should not get here")
-        except Exception as e:
-            resp = e.response.json()
-            self.assertEqual(resp["error"], "no_usable_index")
-
-    def test_three_index_one(self):
-        self.db.create_index(["cars", "age", "name"], name="cars-age-name")
-        selector = {"cars": "2", "age": 10, "name": {"$gt": "AA"}}
-        explain = self.db.find(selector, sort=["name"], explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age-name")
-
-    def test_three_index_two(self):
-        self.db.create_index(["cars", "age", "name"], name="cars-age-name")
-        selector = {"cars": "2", "name": "Eddie", "age": {"$gt": 10}}
-        explain = self.db.find(selector, sort=["age"], explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age-name")
-
-    def test_three_index_fails(self):
-        self.db.create_index(["cars", "age", "name"], name="cars-age-name")
-        selector = {"name": "Eddie", "age": {"$gt": 1}, "cars": {"$gt": "1"}}
-        try:
-            self.db.find(selector, sort=["name"])
-            raise Exception("Should not get here")
-        except Exception as e:
-            resp = e.response.json()
-            self.assertEqual(resp["error"], "no_usable_index")
-
-    def test_empty_sort(self):
-        self.db.create_index(["cars", "age", "name"], name="cars-age-name")
-        selector = {"name": {"$gt": "Eddie"}, "age": 10, "cars": {"$gt": "1"}}
-        explain = self.db.find(selector, explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age-name")
-
-    def test_in_between(self):
-        self.db.create_index(["cars", "age", "name"], name="cars-age-name")
-        selector = {"name": "Eddie", "age": 10, "cars": {"$gt": "1"}}
-        explain = self.db.find(selector, explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age-name")
-
-        try:
-            self.db.find(selector, sort=["cars", "name"])
-            raise Exception("Should not get here")
-        except Exception as e:
-            resp = e.response.json()
-            self.assertEqual(resp["error"], "no_usable_index")
-
-    def test_ignore_after_set_sort_value(self):
-        self.db.create_index(["cars", "age", "name"], name="cars-age-name")
-        selector = {"age": {"$gt": 10}, "cars": 2, "name": {"$gt": "A"}}
-        explain = self.db.find(selector, sort=["age"], explain=True)
-        self.assertEqual(explain["index"]["name"], "cars-age-name")
-
-    def test_not_use_index_if_other_fields_in_sort(self):
-        self.db.create_index(["cars", "age"], name="cars-age")
-        selector = {"age": 10, "cars": {"$gt": "1"}}
-        try:
-            self.db.find(selector, sort=["cars", "name"])
-            raise Exception("Should not get here")
-        except Exception as e:
-            resp = e.response.json()
-            self.assertEqual(resp["error"], "no_usable_index")
diff --git a/test/elixir/test/config/suite.elixir b/test/elixir/test/config/suite.elixir
index b3fb950846c..80671e89f14 100644
--- a/test/elixir/test/config/suite.elixir
+++ b/test/elixir/test/config/suite.elixir
@@ -735,5 +735,19 @@
   ],
   "IgnoreDesignDocsForAllDocsIndexTests": [
     "should not return design docs"
+  ],
+  "JSONIndexSortOptimisations": [
+    "test_works_for_basic_case",
+    "test_works_for_all_fields_specified",
+    "test_works_for_no_sort_fields_specified",
+    "test_works_for_opp_dir_sort",
+    "test_not_work_for_non_constant_field",
+    "test_three_index_one",
+    "test_three_index_two",
+    "test_three_index_fails",
+    "test_empty_sort",
+    "test_in_between",
+    "test_ignore_after_set_sort_value",
+    "test_not_use_index_if_other_fields_in_sort"
   ]
 }
diff --git a/test/elixir/test/mango/18_json_sort.exs b/test/elixir/test/mango/18_json_sort.exs
new file mode 100644
index 00000000000..ab59cd76a67
--- /dev/null
+++ b/test/elixir/test/mango/18_json_sort.exs
@@ -0,0 +1,136 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+
+defmodule JSONIndexSortOptimisations do
+  use CouchTestCase
+
+  @db_name "json-sort-docs"
+  @docs [
+    %{"_id" => "1", "name" => "Jimi", "age" => 10, "cars" => 1},
+    %{"_id" => "2", "name" => "Eddie", "age" => 20, "cars" => 1},
+    %{"_id" => "3", "name" => "Jane", "age" => 30, "cars" => 2},
+    %{"_id" => "4", "name" => "Mary", "age" => 40, "cars" => 2},
+    %{"_id" => "5", "name" => "Sam", "age" => 50, "cars" => 3}
+  ]
+
+  setup do
+    MangoDatabase.recreate(@db_name)
+    MangoDatabase.save_docs(@db_name, @docs)
+    :ok
+  end
+
+  test "test_works_for_basic_case" do
+    MangoDatabase.create_index(@db_name, ["cars", "age"], name: "cars-age")
+    selector = %{"cars" => "2", "age" => %{"$gt" => 10}}
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, sort: ["age"], explain: true)
+
+    assert explain["index"]["name"] == "cars-age"
+    assert explain["mrargs"]["direction"] == "fwd"
+  end
+
+  test "test_works_for_all_fields_specified" do
+    MangoDatabase.create_index(@db_name, ["cars", "age"], name: "cars-age")
+    selector = %{"cars" => "2", "age" => %{"$gt" => 10}}
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, sort: ["cars", "age"], explain: true)
+
+    assert explain["index"]["name"] == "cars-age"
+  end
+
+  test "test_works_for_no_sort_fields_specified" do
+    MangoDatabase.create_index(@db_name, ["cars", "age"], name: "cars-age")
+    selector = %{"cars" => %{"$gt" => 10}, "age" => %{"$gt" => 10}}
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, explain: true)
+
+    assert explain["index"]["name"] == "cars-age"
+  end
+
+  test "test_works_for_opp_dir_sort" do
+    MangoDatabase.create_index(@db_name, ["cars", "age"], name: "cars-age")
+    selector = %{"cars" => "2", "age" => %{"$gt" => 10}}
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, sort: [%{"age" => "desc"}], explain: true)
+
+    assert explain["index"]["name"] == "cars-age"
+    assert explain["mrargs"]["direction"] == "rev"
+  end
+
+  test "test_not_work_for_non_constant_field" do
+    MangoDatabase.create_index(@db_name, ["cars", "age"], name: "cars-age")
+    selector = %{"cars" => %{"$gt" => 10}, "age" => %{"$gt" => 10}}
+    {:error, resp} = MangoDatabase.find(@db_name, selector, sort: ["age"])
+
+    assert resp.body["error"] == "no_usable_index"
+    assert resp.status_code == 400
+  end
+
+  test "test_three_index_one" do
+    MangoDatabase.create_index(@db_name, ["cars", "age", "name"], name: "cars-age-name")
+    selector = %{"cars" => "2", "age" => 10, "name" => %{"$gt" => "AA"}}
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, sort: ["name"], explain: true)
+
+    assert explain["index"]["name"] == "cars-age-name"
+  end
+
+  test "test_three_index_two" do
+    MangoDatabase.create_index(@db_name, ["cars", "age", "name"], name: "cars-age-name")
+    selector = %{"cars" => "2", "name" => "Eddie", "age" => %{"$gt" => 10}}
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, sort: ["age"], explain: true)
+
+    assert explain["index"]["name"] == "cars-age-name"
+  end
+
+  test "test_three_index_fails" do
+    MangoDatabase.create_index(@db_name, ["cars", "age", "name"], name: "cars-age-name")
+    selector = %{"name" => "Eddie", "age" => %{"$gt" => 1}, "cars" => %{"$gt" => "1"}}
+    {:error, response} = MangoDatabase.find(@db_name, selector, sort: ["name"])
+
+    assert response.body["error"] == "no_usable_index"
+    assert response.status_code == 400
+  end
+
+  test "test_empty_sort" do
+    MangoDatabase.create_index(@db_name, ["cars", "age", "name"], name: "cars-age-name")
+    selector = %{"name" => %{"$gt" => "Eddie"}, "age" => 10, "cars" => %{"$gt" => "1"}}
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, explain: true)
+
+    assert explain["index"]["name"] == "cars-age-name"
+  end
+
+  test "test_in_between" do
+    MangoDatabase.create_index(@db_name, ["cars", "age", "name"], name: "cars-age-name")
+    selector = %{"name" => "Eddie", "age" => 10, "cars" => %{"$gt" => "1"}}
+
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, explain: true)
+    assert explain["index"]["name"] == "cars-age-name"
+
+    {:error, response} = MangoDatabase.find(@db_name, selector, sort: ["cars", "name"])
+    assert response.body["error"] == "no_usable_index"
+    assert response.status_code == 400
+  end
+
+  test "test_ignore_after_set_sort_value" do
+    MangoDatabase.create_index(@db_name, ["cars", "age", "name"], name: "cars-age-name")
+    selector = %{"age" => %{"$gt" => 10}, "cars" => 2, "name" => %{"$gt" => "A"}}
+    {:ok, explain} = MangoDatabase.find(@db_name, selector, sort: ["age"], explain: true)
+
+    assert explain["index"]["name"] == "cars-age-name"
+  end
+
+  test "test_not_use_index_if_other_fields_in_sort" do
+    MangoDatabase.create_index(@db_name, ["cars", "age"], name: "cars-age")
+    selector = %{"age" => 10, "cars" => %{"$gt" => "1"}}
+
+    {:error, response} = MangoDatabase.find(@db_name, selector, sort: ["cars", "name"])
+    assert response.body["error"] == "no_usable_index"
+    assert response.status_code == 400
+  end
+
+end