diff --git a/modules/ciphers/atbash.py b/modules/ciphers/atbash.py
index 56b56fa2..c84afd28 100644
--- a/modules/ciphers/atbash.py
+++ b/modules/ciphers/atbash.py
@@ -1,4 +1,5 @@
 import string
+import sys
 
 import click
 
@@ -28,7 +29,7 @@ def encrypt(self, message):
         for char in message:
             if char not in self.alphabet and char != " ":
                 click.echo("Atbash only supports ASCII characters.")
-                return
+                sys.exit(1)
 
             encrypted_message += self.key[char]
         return encrypted_message
diff --git a/modules/ciphers/caesar.py b/modules/ciphers/caesar.py
index aeb1dee9..948da800 100644
--- a/modules/ciphers/caesar.py
+++ b/modules/ciphers/caesar.py
@@ -1,6 +1,7 @@
 import collections
 import itertools
 import string
+import sys
 
 import click
 
@@ -20,7 +21,7 @@ def encrypt(self, message):
         for char in message:
             if char not in string.ascii_uppercase and char != " ":
                 click.echo("The Caesar Cipher only supports ASCII characters")
-                return
+                sys.exit(1)
 
             if char == " ":
                 encrypted_text += " "
@@ -41,7 +42,7 @@ def decrypt(self, message):
         for char in message:
             if char not in string.ascii_uppercase and char != " ":
                 click.echo("The Caesar Cipher only supports ASCII characters")
-                return
+                sys.exit(1)
 
             if char == " ":
                 decrypted_text += " "
diff --git a/modules/ciphers/rot13.py b/modules/ciphers/rot13.py
index c19bc3d6..7d22188c 100644
--- a/modules/ciphers/rot13.py
+++ b/modules/ciphers/rot13.py
@@ -1,6 +1,7 @@
 import collections
 import itertools
 import string
+import sys
 
 import click
 
@@ -31,7 +32,7 @@ def encrypt(self, message):
         for char in message:
             if char not in string.ascii_uppercase and char != " ":
                 click.echo("The ROT13 Cipher only supports ASCII characters")
-                return
+                sys.exit(1)
 
             if char == " ":
                 encrypted_text += " "
@@ -49,7 +50,7 @@ def decrypt(self, message):
         for char in message:
             if char not in string.ascii_uppercase and char != " ":
                 click.echo("The ROT13 Cipher only supports ASCII characters")
-                return
+                sys.exit(1)
 
             if char == " ":
                 decrypted_text += " "
diff --git a/modules/dev.py b/modules/dev.py
index 7b16240c..df106010 100644
--- a/modules/dev.py
+++ b/modules/dev.py
@@ -730,7 +730,7 @@ def ciphers(ctx, mode):
     mode = get_arguments(ctx, 1)
     if mode is None:
         click.echo("No mode was passed.(choose encrypt or decrypt")
-        return
+        sys.exit(1)
 
     _mode = str(mode).lower()
 
@@ -747,7 +747,7 @@ def ciphers(ctx, mode):
     cipher_choice = int(click.prompt("Choose a cipher"))
     if cipher_choice > len(cipher_dict) - 1 or cipher_choice < 0:
         click.echo("Invalid cipher number was chosen.")
-        return
+        sys.exit(1)
 
     cipher = cipher_dict[list(cipher_dict.keys())[cipher_choice]]()
 
@@ -758,7 +758,8 @@ def ciphers(ctx, mode):
         cipher_text = click.prompt("The text you want to decrypt")
         return click.echo(cipher.decrypt(cipher_text))
     else:
-        return click.echo("Invalid mode passed.")
+        click.echo("Invalid mode passed.")
+        sys.exit(1)
 
 
 @dev.command()
diff --git a/tests/ciphers/__init__.py b/tests/ciphers/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/ciphers/test_atbash.py b/tests/ciphers/test_atbash.py
new file mode 100644
index 00000000..69dfcf18
--- /dev/null
+++ b/tests/ciphers/test_atbash.py
@@ -0,0 +1,45 @@
+# coding=utf-8
+import unittest
+from click.testing import CliRunner
+
+import yoda
+
+
+class TestAtbash(unittest.TestCase):
+    """
+        Test for the following commands:
+
+        | Module: ciphers
+        | command: ciphers
+        | args: encrypt
+        | input: 0 <text>
+    """
+
+    def __init__(self, methodName="runTest"):
+        super(TestAtbash, self).__init__()
+        self.runner = CliRunner()
+
+    def runTest(self):
+        # testing for invalid text input for Atbash encryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "encrypt"],
+                                    input="0\n$#$#")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for invalid text input for Atbash decryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "decrypt"],
+                                    input="0\n12345")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for working Atbash encryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "encrypt"],
+                                    input="0\nsample")
+        self.assertEqual(result.exit_code, 0)
+
+        # testing for working Atbash decryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "decrypt"],
+                                    input="0\nsample")
+        self.assertEqual(result.exit_code, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/ciphers/test_ceaser.py b/tests/ciphers/test_ceaser.py
new file mode 100644
index 00000000..71dacb66
--- /dev/null
+++ b/tests/ciphers/test_ceaser.py
@@ -0,0 +1,55 @@
+# coding=utf-8
+import unittest
+from click.testing import CliRunner
+
+import yoda
+
+
+class TestCeaser(unittest.TestCase):
+    """
+        Test for the following commands:
+
+        | Module: ciphers
+        | command: ciphers
+        | args: encrypt
+        | input: 1 <text> <shift>
+    """
+
+    def __init__(self, methodName="runTest"):
+        super(TestCeaser, self).__init__()
+        self.runner = CliRunner()
+
+    def runTest(self):
+        # testing for invalid shift input for ceaser encryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "encrypt"],
+                                    input="1\nsample\na")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for invalid shift input for ceaser decryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "decrypt"],
+                                    input="1\nsample\na")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for invalid text input for ceaser encryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "encrypt"],
+                                    input="1\n$#$#\n3")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for invalid text input for ceaser decryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "decrypt"],
+                                    input="1\n12345\n3")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for working ceaser encryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "encrypt"],
+                                    input="1\nsample\n3")
+        self.assertEqual(result.exit_code, 0)
+
+        # testing for working ceaser decryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "decrypt"],
+                                    input="1\nsample\n3")
+        self.assertEqual(result.exit_code, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/ciphers/test_input.py b/tests/ciphers/test_input.py
new file mode 100644
index 00000000..26b18a75
--- /dev/null
+++ b/tests/ciphers/test_input.py
@@ -0,0 +1,44 @@
+# coding=utf-8
+import unittest
+from click.testing import CliRunner
+
+import yoda
+
+
+class TestInput(unittest.TestCase):
+    """
+        Test for the following commands:
+
+        | Module: ciphers
+        | command: ciphers
+        | args: encrypt
+        | input: 0 <text> <shift>
+    """
+
+    def __init__(self, methodName="runTest"):
+        super(TestInput, self).__init__()
+        self.runner = CliRunner()
+
+    def runTest(self):
+        # testing for no mode passed for ciphers
+        result = self.runner.invoke(yoda.cli, ["ciphers"])
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for invalid cipher input selection in encrypt mode
+        result = self.runner.invoke(yoda.cli, ["ciphers", "encrypt"],
+                                    input="3\nsample\na")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for invalid cipher input selection in decrypt mode
+        result = self.runner.invoke(yoda.cli, ["ciphers", "decrypt"],
+                                    input="3\nsample\na")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for invalid cipher mode
+        result = self.runner.invoke(yoda.cli, ["ciphers", "abc"],
+                                    input="3\nsample\na")
+        self.assertNotEqual(result.exit_code, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/ciphers/test_rot13.py b/tests/ciphers/test_rot13.py
new file mode 100644
index 00000000..b5461db9
--- /dev/null
+++ b/tests/ciphers/test_rot13.py
@@ -0,0 +1,45 @@
+# coding=utf-8
+import unittest
+from click.testing import CliRunner
+
+import yoda
+
+
+class TestRot13(unittest.TestCase):
+    """
+        Test for the following commands:
+
+        | Module: ciphers
+        | command: ciphers
+        | args: encrypt
+        | input: 2 <text>
+    """
+
+    def __init__(self, methodName="runTest"):
+        super(TestRot13, self).__init__()
+        self.runner = CliRunner()
+
+    def runTest(self):
+        # testing for invalid text input for rot13 encryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "encrypt"],
+                                    input="2\nabc1!")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for invalid text input for rot13 decryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "decrypt"],
+                                    input="2\n12345")
+        self.assertNotEqual(result.exit_code, 0)
+
+        # testing for working rot13 encryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "encrypt"],
+                                    input="2\nsample")
+        self.assertEqual(result.exit_code, 0)
+
+        # testing for working rot13 decryption
+        result = self.runner.invoke(yoda.cli, ["ciphers", "decrypt"],
+                                    input="2\nsample")
+        self.assertEqual(result.exit_code, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()