diff --git a/greenmine/base/exceptions.py b/greenmine/base/exceptions.py
index 73a122b7..f293165e 100644
--- a/greenmine/base/exceptions.py
+++ b/greenmine/base/exceptions.py
@@ -4,20 +4,58 @@ from rest_framework import exceptions
 from rest_framework import status
 
 
-class PermissionDenied(exceptions.PermissionDenied):
-    pass
-
-
-class NotFound(exceptions.APIException):
-    status_code = status.HTTP_404_NOT_FOUND
-    default_detail = "Not found"
+class BaseException(exceptions.APIException):
+    status_code = status.HTTP_400_BAD_REQUEST
+    default_detail = 'Unexpected error'
 
     def __init__(self, detail=None):
         self.detail = detail or self.default_detail
 
 
-class BadRequest(exceptions.ParseError):
-    default_detail = "Bad request"
+class NotFound(BaseException):
+    """
+    Exception used for not found objects.
+    """
+
+    status_code = status.HTTP_404_NOT_FOUND
+    default_detail = 'Not found.'
 
 
-__all__ = ["PermissionDenied", "NotFound", "BadRequest"]
+class BadRequest(BaseException):
+    """
+    Exception used on bad arguments detected
+    on api view.
+    """
+    default_detail = 'Wrong arguments.'
+
+
+class WrongArguments(BaseException):
+    """
+    Exception used on bad arguments detected
+    on service. This is same as `BadRequest`.
+    """
+    default_detail = 'Wrong arguments.'
+
+
+class PermissionDenied(exceptions.PermissionDenied):
+    """
+    Compatibility subclass of restframework `PermissionDenied`
+    exception.
+    """
+    pass
+
+
+class InternalError(BaseException):
+    """
+    Exception for internal errors.
+    """
+    status_code = status.HTTP_500_INTERNAL_SERVER_ERROR
+    default_detail = "Internal server error"
+
+
+class NotAuthenticated(exceptions.NotAuthenticated):
+    """
+    Compatibility subclass of restframework `NotAuthenticated`
+    exception.
+    """
+    pass