diff --git a/Classes/Service/PlaintextService.php b/Classes/Service/PlaintextService.php
index 196186ad3580a61deccea2e439db85bf14e8ab5b..57b963cb985b63f687dc0945ce64fc4405ecc370 100644
--- a/Classes/Service/PlaintextService.php
+++ b/Classes/Service/PlaintextService.php
@@ -99,7 +99,7 @@ class PlaintextService {
 	 * @param string $content
 	 * @return array
 	 */
-	protected function addLineBreaks($content) {
+	protected function addLineBreaks($content): array {
 		$tags2LineBreaks = [
 			'</p>',
 			'</tr>',
diff --git a/Classes/Service/RegisterService.php b/Classes/Service/RegisterService.php
index 99695873844c8550319a9f51a9440fa77cf24042..0bb10eb4d521147d78ffe0c7cb361278d433d88c 100644
--- a/Classes/Service/RegisterService.php
+++ b/Classes/Service/RegisterService.php
@@ -130,9 +130,9 @@ class RegisterService implements \TYPO3\CMS\Core\SingletonInterface {
 				$pathAsArray = GeneralUtility::trimExplode('/', $pathToRegistrationFile);
 				$filename = $pathAsArray[\count($pathAsArray) - 1];
 				$filenameWithoutHash = GeneralUtility::trimExplode('_', $filename, FALSE, 2)[1];
-				$hash = md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $filenameWithoutHash);
+				$hash = \md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $filenameWithoutHash);
 				// if the filename doesn't start with the hash value, ignore it
-				if (strpos($filename, $hash) !== 0) {
+				if (\strpos($filename, $hash) !== 0) {
 					continue;
 				}
 
@@ -240,7 +240,7 @@ class RegisterService implements \TYPO3\CMS\Core\SingletonInterface {
 		$registerFolder = GeneralUtility::getFileAbsFileName($configurationLocation);
 		GeneralUtility::mkdir_deep($registerFolder);
 
-		$hashPrefix = md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $templateKey . '.php');
+		$hashPrefix = \md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $templateKey . '.php');
 		$registerFile = GeneralUtility::getFileAbsFileName(
 			$registerFolder . '/' . $hashPrefix . '_' . $templateKey . '.php'
 		);
@@ -268,7 +268,7 @@ class RegisterService implements \TYPO3\CMS\Core\SingletonInterface {
 			];
 		}
 
-		file_put_contents($registerFile, '<?php return ' . var_export($newRegisterArray, TRUE) . ';');
+		\file_put_contents($registerFile, '<?php return ' . \var_export($newRegisterArray, TRUE) . ';');
 
 		return $registerFile;
 	}
@@ -283,11 +283,11 @@ class RegisterService implements \TYPO3\CMS\Core\SingletonInterface {
 		$registerFolder = GeneralUtility::getFileAbsFileName($configurationLocation);
 		GeneralUtility::mkdir_deep($registerFolder);
 
-		$hashPrefix = md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $templateKey . '.php');
+		$hashPrefix = \md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $templateKey . '.php');
 		$registerFile = GeneralUtility::getFileAbsFileName(
 			$registerFolder . '/' . $hashPrefix . '_' . $templateKey . '.php'
 		);
-		if (file_exists($registerFile)) {
+		if (\file_exists($registerFile)) {
 			\unlink($registerFile);
 		}
 	}
@@ -340,13 +340,13 @@ class RegisterService implements \TYPO3\CMS\Core\SingletonInterface {
 		GeneralUtility::mkdir_deep($registerFolder);
 
 		if ($filePath === '') {
-			$hashPrefix = md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $templateName . '.php');
+			$hashPrefix = \md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $templateName . '.php');
 			$filePath = GeneralUtility::getFileAbsFileName(
 				$registerFolder . '/' . $hashPrefix . '_' . $templateName . '.php'
 			);
 		}
 
-		if (file_exists($filePath)) {
+		if (\file_exists($filePath)) {
 			$success = \unlink($filePath);
 		} else {
 			return FALSE;
@@ -383,7 +383,7 @@ class RegisterService implements \TYPO3\CMS\Core\SingletonInterface {
 		$registerFolder = GeneralUtility::getFileAbsFileName($configurationLocation);
 		GeneralUtility::mkdir_deep($registerFolder);
 
-		$hashPrefix = md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $templateName . '.php');
+		$hashPrefix = \md5($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . '|' . $templateName . '.php');
 		$filePath = GeneralUtility::getFileAbsFileName(
 			$registerFolder . '/' . $hashPrefix . '_' . $templateName . '.php'
 		);