diff --git a/README.md b/README.md
index 8d72a37..6858d37 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ Loads the Iconify icon script on every page so Iconify icons can be used in temp
 
 ## Requirements
 
-- phpBB 3.3.0 or later
+- phpBB 3.3.19 or later
 - PHP 7.4 or later
 
 ## Installation
diff --git a/composer.json b/composer.json
index 9f5942f..adfdf13 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,7 @@
     "extra": {
         "display-name": "Insert Iconify Script",
         "soft-require": {
-            "phpbb/phpbb": ">=3.3.0,<4.0.0@dev"
+            "phpbb/phpbb": ">=3.3.19,<4.0.0@dev"
         }
     }
 }
diff --git a/ext.php b/ext.php
index 5dc522a..8209d49 100644
--- a/ext.php
+++ b/ext.php
@@ -21,13 +21,23 @@ class ext extends \phpbb\extension\base
 	const OLD_EXT_NAME = 'modders/inserticonifyscript';
 
 	/**
+	 * Refuse to enable below the minimum phpBB and PHP versions.
+	 *
 	 * Refuse to enable while the old copy is still enabled, otherwise both
 	 * would load the Iconify script twice.
 	 *
-	 * @return bool|array True if enableable, otherwise an array of reasons
+	 * @return bool|string|array True if enableable, otherwise a reason string or array of reasons
 	 */
 	public function is_enableable()
 	{
+		if (!$this->check_phpbb_version() || !$this->check_php_version())
+		{
+			$language = $this->container->get('language');
+			$language->add_lang('install_inserticonifyscript', 'phpbbmodders/inserticonifyscript');
+
+			return $language->lang('INSERTICONIFYSCRIPT_NOT_ENABLEABLE');
+		}
+
 		$ext_manager = $this->container->get('ext.manager');
 
 		if ($ext_manager->is_enabled(self::OLD_EXT_NAME))
@@ -38,6 +48,26 @@ public function is_enableable()
 		return true;
 	}
 
+	/**
+	 * Require phpBB 3.3.19
+	 *
+	 * @return bool
+	 */
+	public function check_phpbb_version()
+	{
+		return phpbb_version_compare(PHPBB_VERSION, '3.3.19', '>=');
+	}
+
+	/**
+	 * Require PHP 7.4
+	 *
+	 * @return bool
+	 */
+	public function check_php_version()
+	{
+		return PHP_VERSION_ID >= 70400;
+	}
+
 	/**
 	 * Remove the disabled old "modders/inserticonifyscript" record so it doesn't linger in
 	 * the extension list after the rename, then enable as usual.
diff --git a/language/en/install_inserticonifyscript.php b/language/en/install_inserticonifyscript.php
new file mode 100644
index 0000000..a78cce9
--- /dev/null
+++ b/language/en/install_inserticonifyscript.php
@@ -0,0 +1,42 @@
+<?php
+/**
+ *
+ * Insert Iconify Script extension for the phpBB Forum Software package
+ *
+ * @copyright (c) 2024, phpBB Modders, https://www.phpbbmodders.com/
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ */
+
+/**
+ * DO NOT CHANGE
+ */
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+if (empty($lang) || !is_array($lang))
+{
+	$lang = [];
+}
+
+// DEVELOPERS PLEASE NOTE
+//
+// All language files should use UTF-8 as their encoding and the files must not contain a BOM.
+//
+// Placeholders can now contain order information, e.g. instead of
+// 'Page %s of %s' you can (and should) write 'Page %1$s of %2$s', this allows
+// translators to re-order the output of data while ensuring it remains correct
+//
+// You do not need this where single placeholders are used, e.g. 'Message %d' is fine
+// equally where a string contains only two placeholders which are used to wrap text
+// in a url you again do not need to specify an order e.g., 'Click %sHERE%s' is fine
+//
+// Some characters you may want to copy&paste:
+// ’ » “ ” …
+//
+
+$lang = array_merge($lang, [
+	'INSERTICONIFYSCRIPT_NOT_ENABLEABLE'	=> 'Insert Iconify Script could not be enabled. The minimum requirements of phpBB 3.3.19 and/or PHP 7.4.0 were not satisfied.',
+]);