diff --git a/phpBB/includes/acp/acp_users.php b/phpBB/includes/acp/acp_users.php
index f730e7cfbe..fc7f3bb56a 100644
--- a/phpBB/includes/acp/acp_users.php
+++ b/phpBB/includes/acp/acp_users.php
@@ -371,11 +371,6 @@ class acp_users
 								if ($user_row['user_type'] == USER_NORMAL)
 								{
 									user_active_flip('deactivate', $user_id, INACTIVE_REMIND);
-
-									$sql = 'UPDATE ' . USERS_TABLE . "
-										SET user_actkey = '" . $db->sql_escape($user_actkey) . "'
-										WHERE user_id = $user_id";
-									$db->sql_query($sql);
 								}
 								else
 								{
@@ -384,8 +379,18 @@ class acp_users
 										FROM ' . USERS_TABLE . '
 										WHERE user_id = ' . $user_id;
 									$result = $db->sql_query($sql);
-									$user_actkey = (string) $db->sql_fetchfield('user_actkey');
+									$user_activation_key = (string) $db->sql_fetchfield('user_actkey');
 									$db->sql_freeresult($result);
+
+									$user_actkey = empty($user_activation_key) ? $user_actkey : $user_activation_key;
+								}
+
+								if ($user_row['user_type'] == USER_NORMAL || empty($user_activation_key))
+								{
+									$sql = 'UPDATE ' . USERS_TABLE . "
+										SET user_actkey = '" . $db->sql_escape($user_actkey) . "'
+										WHERE user_id = $user_id";
+									$db->sql_query($sql);
 								}
 
 								$messenger = new messenger(false);
diff --git a/tests/functional/user_password_reset_test.php b/tests/functional/user_password_reset_test.php
index f9406f0eb5..3da78407cf 100644
--- a/tests/functional/user_password_reset_test.php
+++ b/tests/functional/user_password_reset_test.php
@@ -113,6 +113,49 @@ class phpbb_functional_user_password_reset_test extends phpbb_functional_test_ca
 		$this->assertContains($this->lang('LOGIN_ERROR_PASSWORD', '', ''), $crawler->filter('html')->text());
 	}
 
+	/**
+	 * @depends test_login
+	 */
+	public function test_acivateAfterDeactivate()
+	{
+		// User is active, actkey should not exist
+		$this->get_user_data();
+		$this->assertEmpty($this->user_data['user_actkey']);
+
+		$this->login();
+		$this->admin_login();
+		$this->add_lang('acp/users');
+
+		// Go to user account page
+		$crawler = self::request('GET', 'adm/index.php?i=acp_users&mode=overview&sid=' . $this->sid);
+		$this->assertContainsLang('FIND_USERNAME', $crawler->filter('html')->text());
+
+		$form = $crawler->selectButton('Submit')->form();
+		$crawler = self::submit($form, array('username' => 'reset-password-test-user'));
+
+		// Deactivate account and go back to overview of current user
+		$this->assertContainsLang('USER_TOOLS', $crawler->filter('html')->text());
+		$form = $crawler->filter('input[name=update]')->selectButton('Submit')->form();
+		$crawler = self::submit($form, array('action' => 'active'));
+
+		$this->assertContainsLang('USER_ADMIN_DEACTIVED', $crawler->filter('html')->text());
+		$link = $crawler->selectLink('Back to previous page')->link();
+		$crawler = self::request('GET', preg_replace('#(.+)(adm/index.php.+)#', '$2', $link->getUri()));
+
+		// Ensure again that actkey is empty after deactivation
+		$this->get_user_data();
+		$this->assertEmpty($this->user_data['user_actkey']);
+
+		// Force reactivation of account and check that act key is not empty anymore
+		$this->assertContainsLang('USER_TOOLS', $crawler->filter('html')->text());
+		$form = $crawler->filter('input[name=update]')->selectButton('Submit')->form();
+		$crawler = self::submit($form, array('action' => 'reactivate'));
+		$this->assertContainsLang('FORCE_REACTIVATION_SUCCESS', $crawler->filter('html')->text());
+
+		$this->get_user_data();
+		$this->assertNotEmpty($this->user_data['user_actkey']);
+	}
+
 	protected function get_user_data()
 	{
 		$db = $this->get_db();