diff --git a/lib/private/Files/Storage/Local.php b/lib/private/Files/Storage/Local.php
index 6406beaeebc0b..1318b1c401d74 100644
--- a/lib/private/Files/Storage/Local.php
+++ b/lib/private/Files/Storage/Local.php
@@ -279,6 +279,8 @@ public function file_get_contents($path) {
 
 	public function file_put_contents($path, $data) {
 		$oldMask = umask(022);
+		// support Write-Once-Read-Many filesystems
+		$this->unlink($path);
 		$result = file_put_contents($this->getSourcePath($path), $data);
 		umask($oldMask);
 		return $result;
@@ -360,6 +362,10 @@ public function copy($path1, $path2) {
 
 	public function fopen($path, $mode) {
 		$oldMask = umask(022);
+		if ($mode === 'w') {
+			// support Write-Once-Read-Many filesystems
+			$this->unlink($path);
+		}
 		$result = fopen($this->getSourcePath($path), $mode);
 		umask($oldMask);
 		return $result;