diff --git a/README.rst b/README.rst
index 463db7c..5385199 100644
--- a/README.rst
+++ b/README.rst
@@ -32,6 +32,8 @@ Supported Files
 +------------------+------------+-----------+
 | Pipfile.lock     | yes        | yes       |
 +------------------+------------+-----------+
+| poetry.lock      | yes        | no        |
++------------------+------------+-----------+
 | setup.py         | no (# 2_)  | no (# 2_) |
 +------------------+------------+-----------+
 | zc.buildout      | no (# 3_)  | no (# 3_) |
diff --git a/dparse/errors.py b/dparse/errors.py
index b7a6543..74fc99d 100644
--- a/dparse/errors.py
+++ b/dparse/errors.py
@@ -1,8 +1,19 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals, absolute_import
 
+
 class UnknownDependencyFileError(Exception):
     """
 
     """
-    pass
+    def __init__(self, message="Unknown File type to parse"):
+        self.message = message
+        super().__init__(self.message)
+
+
+class MalformedDependencyFileError(Exception):
+
+    def __init__(self, message="The dependency file is malformed. {info}",
+                 info=""):
+        self.message = message.format(info=info)
+        super().__init__(self.message)