diff --git a/application/config/config.php b/application/config/config.php
index 6e52bcc..c5eae8f 100644
--- a/application/config/config.php
+++ b/application/config/config.php
@@ -213,8 +213,8 @@
 | Encryption Key
 |--------------------------------------------------------------------------
 |
-| If you use the Encryption class or the Sessions class with encryption
-| enabled you MUST set an encryption key.  See the user guide for info.
+| If you use the Encryption class or the Session class you
+| MUST set an encryption key.  See the user guide for info.
 |
 */
 $config['encryption_key'] = "";
diff --git a/system/libraries/Session.php b/system/libraries/Session.php
index cf6dc96..f413c0d 100644
--- a/system/libraries/Session.php
+++ b/system/libraries/Session.php
@@ -65,6 +65,11 @@
 			$this->$key = (isset($params[$key])) ? $params[$key] : $this->CI->config->item($key);
 		}
 
+		if ($this->encryption_key == '')
+		{
+			show_error('In order to use the Session class you are required to set an encryption key in your config file.');
+		}
+
 		// Load the string helper so we can use the strip_slashes() function
 		$this->CI->load->helper('string');
 
diff --git a/user_guide/libraries/sessions.html b/user_guide/libraries/sessions.html
index 9a2ca93..7dc386f 100644
--- a/user_guide/libraries/sessions.html
+++ b/user_guide/libraries/sessions.html
@@ -68,6 +68,9 @@
 <p class="important"><strong>Note:</strong> The Session class does <strong>not</strong> utilize native PHP sessions. It
 generates its own session data, offering more flexibility for developers.</p>
 
+<p class="important"><strong>Note:</strong> Even if you are not using encrypted sessions, you must set
+an encryption key in your config file which is used to aid in preventing session data manipulation.</p>
+
 <h2>Initializing a Session</h2>
 
 <p>Sessions will typically run globally with each page load, so the session class must either be