diff --git a/freqtrade/rpc/api_server.py b/freqtrade/rpc/api_server.py
index bfde304bd..be9f8a6fd 100644
--- a/freqtrade/rpc/api_server.py
+++ b/freqtrade/rpc/api_server.py
@@ -1,3 +1,4 @@
+import json
 import threading
 import logging
 # import json
@@ -138,7 +139,7 @@ class ApiServer(RPC):
         Starts TradeThread in bot if stopped.
         """
         msg = self._rpc_start()
-        return jsonify(msg)
+        return json.dumps(msg)
 
     def stop(self):
         """
@@ -147,4 +148,4 @@ class ApiServer(RPC):
         Stops TradeThread in bot if running
         """
         msg = self._rpc_stop()
-        return jsonify(msg)
+        return json.dumps(msg)
diff --git a/freqtrade/tests/conftest.py b/freqtrade/tests/conftest.py
index ce22cd193..25a9b8d00 100644
--- a/freqtrade/tests/conftest.py
+++ b/freqtrade/tests/conftest.py
@@ -83,6 +83,15 @@ def patch_coinmarketcap(mocker, value: Optional[Dict[str, float]] = None) -> Non
     )
 
 
+def patch_apiserver(mocker) -> None:
+    mocker.patch.multiple(
+        'freqtrade.rpc.api_server.ApiServer',
+        run=MagicMock(),
+        register_rest_other=MagicMock(),
+        register_rest_rpc_urls=MagicMock(),
+    )
+
+
 @pytest.fixture(scope="function")
 def default_conf():
     """ Returns validated configuration suitable for most tests """
diff --git a/freqtrade/tests/rpc/test_rpc_apiserver.py b/freqtrade/tests/rpc/test_rpc_apiserver.py
new file mode 100644
index 000000000..14c35a38e
--- /dev/null
+++ b/freqtrade/tests/rpc/test_rpc_apiserver.py
@@ -0,0 +1,52 @@
+"""
+Unit test file for rpc/api_server.py
+"""
+
+from unittest.mock import MagicMock
+
+from freqtrade.rpc.api_server import ApiServer
+from freqtrade.state import State
+from freqtrade.tests.conftest import get_patched_freqtradebot, patch_apiserver
+
+
+def test__init__(default_conf, mocker):
+    """
+    Test __init__() method
+    """
+    mocker.patch('freqtrade.rpc.telegram.Updater', MagicMock())
+    mocker.patch('freqtrade.rpc.api_server.ApiServer.run', MagicMock())
+
+    apiserver = ApiServer(get_patched_freqtradebot(mocker, default_conf))
+    assert apiserver._config == default_conf
+
+
+def test_start_endpoint(default_conf, mocker):
+    """Test /start endpoint"""
+    patch_apiserver(mocker)
+    bot = get_patched_freqtradebot(mocker, default_conf)
+    apiserver = ApiServer(bot)
+
+    bot.state = State.STOPPED
+    assert bot.state == State.STOPPED
+    result = apiserver.start()
+    assert result == '{"status": "starting trader ..."}'
+    assert bot.state == State.RUNNING
+
+    result = apiserver.start()
+    assert result == '{"status": "already running"}'
+
+
+def test_stop_endpoint(default_conf, mocker):
+    """Test /stop endpoint"""
+    patch_apiserver(mocker)
+    bot = get_patched_freqtradebot(mocker, default_conf)
+    apiserver = ApiServer(bot)
+
+    bot.state = State.RUNNING
+    assert bot.state == State.RUNNING
+    result = apiserver.stop()
+    assert result == '{"status": "stopping trader ..."}'
+    assert bot.state == State.STOPPED
+
+    result = apiserver.stop()
+    assert result == '{"status": "already stopped"}'