diff --git a/.idea/deployment.xml b/.idea/deployment.xml
new file mode 100644
index 0000000..05f0e7d
--- /dev/null
+++ b/.idea/deployment.xml
@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="PublishConfigData">
+    <serverData>
+      <paths name="thepreview">
+        <serverdata>
+          <mappings>
+            <mapping local="$PROJECT_DIR$" web="/" />
+          </mappings>
+        </serverdata>
+      </paths>
+      <paths name="voorvertoning">
+        <serverdata>
+          <mappings>
+            <mapping local="$PROJECT_DIR$" web="/" />
+          </mappings>
+        </serverdata>
+      </paths>
+      <paths name="yourpreview">
+        <serverdata>
+          <mappings>
+            <mapping local="$PROJECT_DIR$" web="/" />
+          </mappings>
+        </serverdata>
+      </paths>
+    </serverData>
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/dictionaries/jonas.xml b/.idea/dictionaries/jonas.xml
new file mode 100644
index 0000000..84b414e
--- /dev/null
+++ b/.idea/dictionaries/jonas.xml
@@ -0,0 +1,3 @@
+<component name="ProjectDictionaryState">
+  <dictionary name="jonas" />
+</component>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
new file mode 100644
index 0000000..28a804d
--- /dev/null
+++ b/.idea/misc.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="JavaScriptSettings">
+    <option name="languageLevel" value="ES6" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..94a25f7
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
new file mode 100644
index 0000000..4e6cb79
--- /dev/null
+++ b/.idea/workspace.xml
@@ -0,0 +1,206 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ChangeListManager">
+    <list default="true" id="845a6389-1bf1-4006-88e9-ec4b3ddfd757" name="Default" comment="">
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/src/CouponCode.php" afterPath="$PROJECT_DIR$/src/CouponCode.php" />
+    </list>
+    <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
+    <option name="TRACKING_ENABLED" value="true" />
+    <option name="SHOW_DIALOG" value="false" />
+    <option name="HIGHLIGHT_CONFLICTS" value="true" />
+    <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
+    <option name="LAST_RESOLUTION" value="IGNORE" />
+  </component>
+  <component name="FileEditorManager">
+    <leaf>
+      <file leaf-file-name="CouponCode.php" pinned="false" current-in-tab="true">
+        <entry file="file://$PROJECT_DIR$/src/CouponCode.php">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="556">
+              <caret line="249" column="10" lean-forward="false" selection-start-line="249" selection-start-column="10" selection-end-line="249" selection-end-column="10" />
+              <folding />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file leaf-file-name="composer.json" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/composer.json">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="306">
+              <caret line="18" column="0" lean-forward="false" selection-start-line="18" selection-start-column="0" selection-end-line="18" selection-end-column="0" />
+              <folding />
+            </state>
+          </provider>
+        </entry>
+      </file>
+    </leaf>
+  </component>
+  <component name="Git.Settings">
+    <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$" />
+  </component>
+  <component name="IdeDocumentHistory">
+    <option name="CHANGED_PATHS">
+      <list>
+        <option value="$PROJECT_DIR$/composer.json" />
+        <option value="$PROJECT_DIR$/src/CouponCode.php" />
+      </list>
+    </option>
+  </component>
+  <component name="JsBuildToolGruntFileManager" detection-done="true" sorting="DEFINITION_ORDER" />
+  <component name="JsBuildToolPackageJson" detection-done="true" sorting="DEFINITION_ORDER" />
+  <component name="JsGulpfileManager">
+    <detection-done>true</detection-done>
+    <sorting>DEFINITION_ORDER</sorting>
+  </component>
+  <component name="PhpWorkspaceProjectConfiguration" backward_compatibility_performed="true" />
+  <component name="ProjectFrameBounds">
+    <option name="x" value="496" />
+    <option name="y" value="13" />
+    <option name="width" value="1720" />
+    <option name="height" value="1400" />
+  </component>
+  <component name="ProjectLevelVcsManager" settingsEditedManually="true">
+    <ConfirmationsSetting value="2" id="Add" />
+  </component>
+  <component name="ProjectView">
+    <navigator currentView="ProjectPane" proportions="" version="1">
+      <flattenPackages />
+      <showMembers />
+      <showModules />
+      <showLibraryContents />
+      <hideEmptyPackages />
+      <abbreviatePackageNames />
+      <autoscrollToSource />
+      <autoscrollFromSource />
+      <sortByType />
+      <manualOrder />
+      <foldersAlwaysOnTop value="true" />
+    </navigator>
+    <panes>
+      <pane id="Scratches" />
+      <pane id="ProjectPane">
+        <subPane>
+          <expand>
+            <path>
+              <item name="coupon_code" type="b2602c69:ProjectViewProjectNode" />
+              <item name="coupon_code" type="2a2b976b:PhpTreeStructureProvider$1" />
+            </path>
+            <path>
+              <item name="coupon_code" type="b2602c69:ProjectViewProjectNode" />
+              <item name="coupon_code" type="2a2b976b:PhpTreeStructureProvider$1" />
+              <item name="src" type="2a2b976b:PhpTreeStructureProvider$1" />
+            </path>
+          </expand>
+          <select />
+        </subPane>
+      </pane>
+      <pane id="Scope" />
+    </panes>
+  </component>
+  <component name="PropertiesComponent">
+    <property name="settings.editor.selected.configurable" value="reference.settings.ide.settings.file-colors" />
+    <property name="nodejs_interpreter_path" value="C:/Program Files/nodejs/node" />
+    <property name="JavaScriptPreferStrict" value="false" />
+    <property name="JavaScriptWeakerCompletionTypeGuess" value="true" />
+    <property name="WebServerToolWindowFactoryState" value="true" />
+  </component>
+  <component name="RunDashboard">
+    <option name="ruleStates">
+      <list>
+        <RuleState>
+          <option name="name" value="ConfigurationTypeDashboardGroupingRule" />
+        </RuleState>
+        <RuleState>
+          <option name="name" value="StatusDashboardGroupingRule" />
+        </RuleState>
+      </list>
+    </option>
+  </component>
+  <component name="ShelveChangesManager" show_recycled="false">
+    <option name="remove_strategy" value="false" />
+  </component>
+  <component name="TaskManager">
+    <task active="true" id="Default" summary="Default task">
+      <changelist id="845a6389-1bf1-4006-88e9-ec4b3ddfd757" name="Default" comment="" />
+      <created>1551357239839</created>
+      <option name="number" value="Default" />
+      <option name="presentableId" value="Default" />
+      <updated>1551357239839</updated>
+      <workItem from="1551357241645" duration="4971000" />
+    </task>
+    <task id="LOCAL-00001" summary="Updated code to use 'random_bytes' instead of 'mcrypt_create_iv'">
+      <created>1551357358782</created>
+      <option name="number" value="00001" />
+      <option name="presentableId" value="LOCAL-00001" />
+      <option name="project" value="LOCAL" />
+      <updated>1551357358784</updated>
+    </task>
+    <task id="LOCAL-00002" summary="Updated code to use 'random_bytes' instead of 'mcrypt_create_iv'">
+      <created>1551359062114</created>
+      <option name="number" value="00002" />
+      <option name="presentableId" value="LOCAL-00002" />
+      <option name="project" value="LOCAL" />
+      <updated>1551359062114</updated>
+    </task>
+    <option name="localTasksCounter" value="3" />
+    <servers />
+  </component>
+  <component name="TimeTrackingManager">
+    <option name="totallyTimeSpent" value="4971000" />
+  </component>
+  <component name="ToolWindowManager">
+    <frame x="496" y="13" width="1720" height="1400" extended-state="0" />
+    <layout>
+      <window_info id="Remote Host" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="-1" side_tool="false" content_ui="tabs" />
+      <window_info id="Project" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="0" side_tool="false" content_ui="combo" />
+      <window_info id="TODO" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="6" side_tool="false" content_ui="tabs" />
+      <window_info id="Event Log" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.33386075" sideWeight="0.50240964" order="-1" side_tool="true" content_ui="tabs" />
+      <window_info id="Database" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="-1" side_tool="false" content_ui="tabs" />
+      <window_info id="Run" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="2" side_tool="false" content_ui="tabs" />
+      <window_info id="Version Control" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.3296875" sideWeight="0.49882215" order="-1" side_tool="false" content_ui="tabs" />
+      <window_info id="Structure" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="1" side_tool="false" content_ui="tabs" />
+      <window_info id="Terminal" active="true" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.33386075" sideWeight="0.49759036" order="-1" side_tool="false" content_ui="tabs" />
+      <window_info id="Debug" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.4" sideWeight="0.5" order="3" side_tool="false" content_ui="tabs" />
+      <window_info id="Favorites" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="-1" side_tool="true" content_ui="tabs" />
+      <window_info id="Cvs" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="4" side_tool="false" content_ui="tabs" />
+      <window_info id="Hierarchy" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="2" side_tool="false" content_ui="combo" />
+      <window_info id="Message" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="0" side_tool="false" content_ui="tabs" />
+      <window_info id="Commander" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.4" sideWeight="0.5" order="0" side_tool="false" content_ui="tabs" />
+      <window_info id="Find" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="1" side_tool="false" content_ui="tabs" />
+      <window_info id="Inspection" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.4" sideWeight="0.5" order="5" side_tool="false" content_ui="tabs" />
+      <window_info id="Ant Build" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="1" side_tool="false" content_ui="tabs" />
+    </layout>
+  </component>
+  <component name="TypeScriptGeneratedFilesManager">
+    <option name="version" value="1" />
+  </component>
+  <component name="VcsContentAnnotationSettings">
+    <option name="myLimit" value="2678400000" />
+  </component>
+  <component name="VcsManagerConfiguration">
+    <MESSAGE value="Updated code to use 'random_bytes' instead of 'mcrypt_create_iv'" />
+    <option name="LAST_COMMIT_MESSAGE" value="Updated code to use 'random_bytes' instead of 'mcrypt_create_iv'" />
+  </component>
+  <component name="XDebuggerManager">
+    <breakpoint-manager />
+    <watches-manager />
+  </component>
+  <component name="editorHistoryManager">
+    <entry file="file://$PROJECT_DIR$/composer.json">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="306">
+          <caret line="18" column="0" lean-forward="false" selection-start-line="18" selection-start-column="0" selection-end-line="18" selection-end-column="0" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/src/CouponCode.php">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="556">
+          <caret line="249" column="10" lean-forward="false" selection-start-line="249" selection-start-column="10" selection-end-line="249" selection-end-column="10" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+  </component>
+</project>
\ No newline at end of file
diff --git a/composer.json b/composer.json
index e1c2c92..cdab91b 100644
--- a/composer.json
+++ b/composer.json
@@ -16,9 +16,6 @@
     "require-dev": {
         "phpunit/phpunit": ">=4.0.0"    
     },
-    "suggest": {
-      "ext-mcrypt": "The mcrypt extension must be installed if /dev/urandom is not available."
-    },
     "autoload": {
         "psr-4": { "CouponCode\\": "src/" }
     }
diff --git a/src/CouponCode.php b/src/CouponCode.php
index ae0be45..ad8f634 100644
--- a/src/CouponCode.php
+++ b/src/CouponCode.php
@@ -233,22 +233,24 @@ protected function _normalize($string, array $options = []) {
 		return $string;
 	}
 
-	/**
-	 * Generates a cryptographically secure sequence of bytes.
-	 *
-	 * @param integer $bytes Number of bytes to return.
-	 * @return string
-	 */
+    /**
+     * Generates a cryptographically secure sequence of bytes.
+     *
+     * @param integer $bytes Number of bytes to return.
+     * @return string
+     * @throws Exception
+     */
 	protected function _random($bytes) {
-		if (is_readable('/dev/urandom')) {
-			$stream = fopen('/dev/urandom', 'rb');
-			$result = fread($stream, $bytes);
+        //if (is_readable('/dev/urandom')) {
+        if ($fh = @fopen('/dev/urandom', 'rb')) {
+            $stream = fopen('/dev/urandom', 'rb');
+            $result = fread($stream, $bytes);
 
-			fclose($stream);
-			return $result;
-		}
-		if (function_exists('mcrypt_create_iv')) {
-			return mcrypt_create_iv($bytes, MCRYPT_DEV_RANDOM);
+            fclose($stream);
+            return $result;
+        }
+		if (function_exists('random_bytes')) {
+			return random_bytes($bytes);
 		}
 		throw new Exception("No source for generating a cryptographically secure seed found.");
 	}