3 files changed, 21 insertions, 0 deletions
diff --git a/phpBB/phpbb/extension/base.php b/phpBB/phpbb/extension/base.php
index 53051ce881..288fb7d19c 100644
--- a/phpBB/phpbb/extension/base.php
+++ b/phpBB/phpbb/extension/base.php
@@ -55,6 +55,14 @@ class base implements \phpbb\extension\extension_interface
 	}
 
 	/**
+	* {@inheritdoc}
+	*/
+	public function is_enableable()
+	{
+		return true;
+	}
+
+	/**
 	* Single enable step that installs any included migrations
 	*
 	* @param mixed $old_state State returned by previous call of this method
diff --git a/phpBB/phpbb/extension/extension_interface.php b/phpBB/phpbb/extension/extension_interface.php
index cc8b8be980..6a6b6adb8f 100644
--- a/phpBB/phpbb/extension/extension_interface.php
+++ b/phpBB/phpbb/extension/extension_interface.php
@@ -20,6 +20,13 @@ namespace phpbb\extension;
 interface extension_interface
 {
 	/**
+	* Indicate whether or not the extension can be enabled.
+	*
+	* @return bool
+	*/
+	public function is_enableable();
+
+	/**
 	* enable_step is executed on enabling an extension until it returns false.
 	*
 	* Calls to this function can be made in subsequent requests, when the
diff --git a/phpBB/phpbb/extension/manager.php b/phpBB/phpbb/extension/manager.php
index 4a12e9ec8c..76f0e3558e 100644
--- a/phpBB/phpbb/extension/manager.php
+++ b/phpBB/phpbb/extension/manager.php
@@ -178,6 +178,12 @@ class manager
 		$old_state = (isset($this->extensions[$name]['ext_state'])) ? unserialize($this->extensions[$name]['ext_state']) : false;
 
 		$extension = $this->get_extension($name);
+
+		if (!$extension->is_enableable())
+		{
+			return false;
+		}
+
 		$state = $extension->enable_step($old_state);
 
 		$active = ($state === false);