diff --git a/index.php b/index.php
index 240b773c..89277b0e 100644
--- a/index.php
+++ b/index.php
@@ -502,7 +502,10 @@ 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
@@ -1136,7 +1139,10 @@ 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 d1f523c5..4e74be7e 100644
--- a/lib/Updater.php
+++ b/lib/Updater.php
@@ -486,7 +486,10 @@ 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
@@ -1120,7 +1123,10 @@ 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($fileName))) {
diff --git a/tests/checkSameCodeBase.php b/tests/checkSameCodeBase.php
index bd1d2c8a..fb106b60 100644
--- a/tests/checkSameCodeBase.php
+++ b/tests/checkSameCodeBase.php
@@ -56,7 +56,7 @@ function findDiffPos($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)) {
 		continue;
diff --git a/updater.phar b/updater.phar
index 70abbee7..b08cc626 100755
Binary files a/updater.phar and b/updater.phar differ