diff --git a/tests/commands/test_build_config.py b/tests/commands/test_build_config.py
index 8f71c2098..d4ebe1de2 100644
--- a/tests/commands/test_build_config.py
+++ b/tests/commands/test_build_config.py
@@ -5,11 +5,33 @@ import pytest
 import rapidjson
 
 from freqtrade.commands.build_config_commands import (ask_user_config,
-                                                      start_new_config)
+                                                      ask_user_overwrite,
+                                                      start_new_config,
+                                                      validate_is_float,
+                                                      validate_is_int)
 from freqtrade.exceptions import OperationalException
 from tests.conftest import get_args, log_has_re
 
 
+def test_validate_is_float():
+    assert validate_is_float('2.0')
+    assert validate_is_float('2.1')
+    assert validate_is_float('0.1')
+    assert validate_is_float('-0.5')
+    assert not validate_is_float('-0.5e')
+
+
+def test_validate_is_int():
+    assert validate_is_int('2')
+    assert validate_is_int('6')
+    assert validate_is_int('-1')
+    assert validate_is_int('500')
+    assert not validate_is_int('2.0')
+    assert not validate_is_int('2.1')
+    assert not validate_is_int('-2.1')
+    assert not validate_is_int('-ee')
+
+
 @pytest.mark.parametrize('exchange', ['bittrex', 'binance', 'kraken', 'ftx'])
 def test_start_new_config(mocker, caplog, exchange):
     wt_mock = mocker.patch.object(Path, "write_text", MagicMock())
@@ -61,7 +83,34 @@ def test_start_new_config_exists(mocker, caplog):
         start_new_config(get_args(args))
 
 
-def test_ask_user_config():
-    # TODO: Implement me
-    pass
-    # assert ask_user_config()
+def test_ask_user_overwrite(mocker):
+    """
+    Once https://github.com/tmbo/questionary/issues/35 is implemented, improve this test.
+    """
+    prompt_mock = mocker.patch('freqtrade.commands.build_config_commands.prompt',
+                               return_value={'overwrite': False})
+    assert not ask_user_overwrite(Path('test.json'))
+    assert prompt_mock.call_count == 1
+
+    prompt_mock.reset_mock()
+    prompt_mock = mocker.patch('freqtrade.commands.build_config_commands.prompt',
+                               return_value={'overwrite': True})
+    assert ask_user_overwrite(Path('test.json'))
+    assert prompt_mock.call_count == 1
+
+
+def test_ask_user_config(mocker):
+    """
+    Once https://github.com/tmbo/questionary/issues/35 is implemented, improve this test.
+    """
+    prompt_mock = mocker.patch('freqtrade.commands.build_config_commands.prompt',
+                               return_value={'overwrite': False})
+    answers = ask_user_config()
+    assert isinstance(answers, dict)
+    assert prompt_mock.call_count == 1
+
+    prompt_mock = mocker.patch('freqtrade.commands.build_config_commands.prompt',
+                               return_value={})
+
+    with pytest.raises(OperationalException, match=r"User interrupted interactive questions\."):
+        ask_user_config()