diff --git a/src/cpl_core/database/database_settings.py b/src/cpl_core/database/database_settings.py
index 609a3075..c8ee032f 100644
--- a/src/cpl_core/database/database_settings.py
+++ b/src/cpl_core/database/database_settings.py
@@ -12,11 +12,11 @@ class DatabaseSettings(ConfigurationModelABC):
         port: int = None,
         user: str = None,
         password: str = None,
-        databse: str = None,
+        database: str = None,
         charset: str = None,
         use_unicode: bool = None,
         buffered: bool = None,
-        auth_plugin: bool = None,
+        auth_plugin: str = None,
     ):
         ConfigurationModelABC.__init__(self)
 
@@ -24,7 +24,7 @@ class DatabaseSettings(ConfigurationModelABC):
         self._port: Optional[int] = port
         self._user: Optional[str] = user
         self._password: Optional[str] = password
-        self._databse: Optional[str] = databse
+        self._databse: Optional[str] = database
         self._charset: Optional[str] = charset
         self._use_unicode: Optional[bool] = use_unicode
         self._buffered: Optional[bool] = buffered
diff --git a/src/cpl_core/utils/json_processor.py b/src/cpl_core/utils/json_processor.py
index 3de2e59d..afa3ea23 100644
--- a/src/cpl_core/utils/json_processor.py
+++ b/src/cpl_core/utils/json_processor.py
@@ -30,6 +30,9 @@ class JSONProcessor:
                 if issubclass(parameter.annotation, enum.Enum):
                     value = parameter.annotation[value]
 
+                if type(value) != parameter.annotation:
+                    value = parameter.annotation(value)
+
                 args.append(value)
 
             elif parameter.default != Parameter.empty:
diff --git a/unittests/unittests_core/configuration/configuration_test_case.py b/unittests/unittests_core/configuration/configuration_test_case.py
new file mode 100644
index 00000000..5e4f113e
--- /dev/null
+++ b/unittests/unittests_core/configuration/configuration_test_case.py
@@ -0,0 +1,37 @@
+import os
+import unittest
+
+from cpl_core.configuration import Configuration
+from cpl_core.database import DatabaseSettings
+from cpl_core.mailing import EMailClientSettings
+
+
+class ConfigurationTestCase(unittest.TestCase):
+    def setUp(self):
+        self._config = Configuration()
+
+    def test_env_vars(self):
+        os.environ["CPLT_TESTVAR"] = "Hello World"
+        os.environ["CPL_NOT_EXISTING"] = "Hello World"
+
+        self._config.add_environment_variables("CPLT_")
+
+        self.assertEqual(self._config.get_configuration("TESTVAR"), "Hello World")
+        self.assertEqual(self._config.get_configuration("TESTVAR"), "Hello World")
+        self.assertEqual(self._config.get_configuration("NOT_EXISTING"), None)
+
+    def test_add_json_file(self):
+        self._config.add_json_file("unittests_core/configuration/test-settings.json")
+        db = self._config.get_configuration(DatabaseSettings)
+        self.assertIsNotNone(db)
+        self.assertEqual("localhost", db.host)
+        self.assertEqual("local", db.user)
+        self.assertEqual("bG9jYWw=", db.password)
+        self.assertEqual("local", db.database)
+        self.assertEqual(int, type(db.port))
+        self.assertEqual(3306, db.port)
+        self.assertEqual("utf8mb4", db.charset)
+        self.assertTrue(db.use_unicode)
+        self.assertTrue(db.buffered)
+        self.assertEqual("mysql_native_password", db.auth_plugin)
+        self.assertIsNone(self._config.get_configuration(EMailClientSettings))
diff --git a/unittests/unittests_core/configuration/test-settings.json b/unittests/unittests_core/configuration/test-settings.json
new file mode 100644
index 00000000..702de250
--- /dev/null
+++ b/unittests/unittests_core/configuration/test-settings.json
@@ -0,0 +1,25 @@
+{
+  "TimeFormatSettings": {
+    "DateFormat": "%Y-%m-%d",
+    "TimeFormat": "%H:%M:%S",
+    "DateTimeFormat": "%Y-%m-%d %H:%M:%S.%f",
+    "DateTimeLogFormat": "%Y-%m-%d_%H-%M-%S"
+  },
+  "LoggingSettings": {
+    "Path": "logs/$date_now/",
+    "Filename": "bot.log",
+    "ConsoleLogLevel": "TRACE",
+    "FileLogLevel": "TRACE"
+  },
+  "DatabaseSettings": {
+    "Host": "localhost",
+    "User": "local",
+    "Password": "bG9jYWw=",
+    "Database": "local",
+    "Port": "3306",
+    "Charset": "utf8mb4",
+    "UseUnicode": "true",
+    "Buffered": "true",
+    "AuthPlugin": "mysql_native_password"
+  }
+}
\ No newline at end of file
diff --git a/unittests/unittests_core/core_test_suite.py b/unittests/unittests_core/core_test_suite.py
index 56304328..39dc4c99 100644
--- a/unittests/unittests_core/core_test_suite.py
+++ b/unittests/unittests_core/core_test_suite.py
@@ -1,5 +1,6 @@
 import unittest
 
+from unittests_core.configuration.configuration_test_case import ConfigurationTestCase
 from unittests_core.configuration.environment_test_case import EnvironmentTestCase
 from unittests_core.pipes.bool_pipe_test_case import BoolPipeTestCase
 from unittests_core.pipes.ip_address_pipe_test_case import IPAddressTestCase
@@ -16,6 +17,7 @@ class CoreTestSuite(unittest.TestSuite):
         loader = unittest.TestLoader()
         tests = [
             # config
+            ConfigurationTestCase,
             EnvironmentTestCase,
             # pipes
             BoolPipeTestCase,
diff --git a/unittests/unittests_core/utils/json_processor_test_case.py b/unittests/unittests_core/utils/json_processor_test_case.py
index 4f969a9d..2772c966 100644
--- a/unittests/unittests_core/utils/json_processor_test_case.py
+++ b/unittests/unittests_core/utils/json_processor_test_case.py
@@ -26,7 +26,7 @@ class JSONProcessorTestCase(unittest.TestCase):
             "i": 10,
             "s": "Hello World",
             "d": {"test": "Test"},
-            "l": range(0, 11),
+            "l": list(range(0, 11)),
             "value": {"value": "Hello World"},
         }
         test: TestClass = JSONProcessor.process(TestClass, test_dict)