diff --git a/index.php b/index.php
index 2beb3fb2..1b993a25 100644
--- a/index.php
+++ b/index.php
@@ -508,7 +508,10 @@ public function createBackup(): void {
 		}
 
 		foreach ($this->getRecursiveDirectoryIterator($this->nextcloudDir, $excludedElements) as $absolutePath => $fileInfo) {
-			$relativePath = explode($this->nextcloudDir, $absolutePath)[1];
+			$relativePath = explode($this->nextcloudDir, $absolutePath, 2)[1] ?? null;
+			if ($relativePath === null) {
+				throw new \Exception($absolutePath . ' is not in ' . $this->nextcloudDir);
+			}
 			$relativeDirectory = dirname($relativePath);
 
 			// Create folder if it doesn't exist
@@ -1180,7 +1183,10 @@ private function moveWithExclusions(string $dataLocation, array $excludedElement
 
 			}
 
-			$fileName = explode($dataLocation, $path)[1];
+			$fileName = explode($dataLocation, $path, 2)[1] ?? null;
+			if ($fileName === null) {
+				throw new \Exception('Could not move ' . $path . ' as it’s not in ' . $dataLocation);
+			}
 
 			if ($fileInfo->isFile()) {
 				if (!file_exists($this->nextcloudDir . '/' . dirname($fileName))) {
diff --git a/lib/Updater.php b/lib/Updater.php
index 665b3a14..96322949 100644
--- a/lib/Updater.php
+++ b/lib/Updater.php
@@ -492,7 +492,10 @@ public function createBackup(): void {
 		}
 
 		foreach ($this->getRecursiveDirectoryIterator($this->nextcloudDir, $excludedElements) as $absolutePath => $fileInfo) {
-			$relativePath = explode($this->nextcloudDir, $absolutePath)[1];
+			$relativePath = explode($this->nextcloudDir, $absolutePath, 2)[1] ?? null;
+			if ($relativePath === null) {
+				throw new \Exception($absolutePath . ' is not in ' . $this->nextcloudDir);
+			}
 			$relativeDirectory = dirname($relativePath);
 
 			// Create folder if it doesn't exist
@@ -1164,7 +1167,10 @@ private function moveWithExclusions(string $dataLocation, array $excludedElement
 
 			}
 
-			$fileName = explode($dataLocation, $path)[1];
+			$fileName = explode($dataLocation, $path, 2)[1] ?? null;
+			if ($fileName === null) {
+				throw new \Exception('Could not move ' . $path . ' as it’s not in ' . $dataLocation);
+			}
 
 			if ($fileInfo->isFile()) {
 				if (!file_exists($this->nextcloudDir . '/' . dirname($fileName))) {
diff --git a/tests/checkSameCodeBase.php b/tests/checkSameCodeBase.php
index 0f87c3dd..703a800a 100644
--- a/tests/checkSameCodeBase.php
+++ b/tests/checkSameCodeBase.php
@@ -56,7 +56,7 @@ function findDiffPos($original, $copy) {
  * @var SplFileInfo $fileInfo
  */
 foreach ($iterator as $path => $fileInfo) {
-	$fileName = explode($libDir, $path)[1];
+	$fileName = explode($libDir, $path, 2)[1];
 
 	if (in_array($fileName, $excludedFiles, true)) {
 		continue;
diff --git a/updater.phar b/updater.phar
index 625fae13..e4189936 100755
Binary files a/updater.phar and b/updater.phar differ
diff --git a/vendor/composer/installed.php b/vendor/composer/installed.php
index 99b12393..b00be49f 100644
--- a/vendor/composer/installed.php
+++ b/vendor/composer/installed.php
@@ -3,7 +3,7 @@
         'name' => '__root__',
         'pretty_version' => 'dev-master',
         'version' => 'dev-master',
-        'reference' => '4123450c26d24ffaa60b2b495e0d8aa934cd982e',
+        'reference' => 'aa4d3f66efadf70396c0ab758da5d105bade36e2',
         'type' => 'library',
         'install_path' => __DIR__ . '/../../',
         'aliases' => array(),
@@ -13,7 +13,7 @@
         '__root__' => array(
             'pretty_version' => 'dev-master',
             'version' => 'dev-master',
-            'reference' => '4123450c26d24ffaa60b2b495e0d8aa934cd982e',
+            'reference' => 'aa4d3f66efadf70396c0ab758da5d105bade36e2',
             'type' => 'library',
             'install_path' => __DIR__ . '/../../',
             'aliases' => array(),