diff --git a/proliantutils/exception.py b/proliantutils/exception.py
index 9d3a8414..c4f4179b 100644
--- a/proliantutils/exception.py
+++ b/proliantutils/exception.py
@@ -24,6 +24,21 @@ class InvalidInputError(Exception):
 
     message = "Invalid Input: %(reason)s"
 
+    # Note(deray): Not mandating the user to provide the ``reason`` attribute
+    # parameter while raising InvalidInputError exception. This is because of
+    # backward-compatibility reasons. See its unit test file to know about its
+    # different ways of usage.
+    def __init__(self, message=None, **kwargs):
+
+        if not message:
+            message = self.message
+
+            if 'reason' not in kwargs:
+                kwargs['reason'] = 'Unknown'
+
+        message = message % kwargs
+        super(InvalidInputError, self).__init__(message)
+
 
 class IloError(ProliantUtilsException):
     """Base Exception.
diff --git a/proliantutils/tests/test_exception.py b/proliantutils/tests/test_exception.py
new file mode 100644
index 00000000..e7ff12e3
--- /dev/null
+++ b/proliantutils/tests/test_exception.py
@@ -0,0 +1,67 @@
+# Copyright 2016 Hewlett Packard Enterprise Development LP
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+"""Test Class for Exception."""
+
+import unittest
+
+import ddt
+
+from proliantutils import exception
+
+
+@ddt.ddt
+class ExceptionTestCase(unittest.TestCase):
+
+    def setUp(self):
+        super(ExceptionTestCase, self).setUp()
+
+    @ddt.data(('check your input',   # input - exception message
+               None,                 # input - exception kwargs
+               'check your input'),  # expected raised exception message
+
+              ('check your input. %(reason)s',
+               {'reason': 'invalid input provided'},
+               'check your input. invalid input provided'),
+
+              ('check your input. %(why)s',
+               {'why': 'invalid input provided'},
+               'check your input. invalid input provided'),
+
+              ("just check your input.. that's all. no any reason given",
+               {'reason': 'some reason'},
+               "just check your input.. that's all. no any reason given"),
+
+              (None,
+               {'reason': 'Input not supported'},
+               'Invalid Input: Input not supported'),
+
+              (None,
+               None,
+               'Invalid Input: Unknown'),)
+    @ddt.unpack
+    def test_InvalidInputError(self, input_exc_message, input_exc_kwargs,
+                               expected_exc_message):
+        # | GIVEN |
+        def raising_invalid_input_error_exc_with(msg, **kwargs):
+            raise exception.InvalidInputError(msg, **kwargs)
+
+        input_exc_kwargs = input_exc_kwargs or {}
+        # | WHEN | & | THEN |
+        with self.assertRaises(exception.InvalidInputError) as cm:
+            raising_invalid_input_error_exc_with(input_exc_message,
+                                                 **input_exc_kwargs)
+
+        the_exception = cm.exception
+        self.assertEqual(expected_exc_message, str(the_exception))