diff --git a/apps/dav/lib/connector/sabre/quotaplugin.php b/apps/dav/lib/connector/sabre/quotaplugin.php
index 0682fca94ea05..484bb5129e870 100644
--- a/apps/dav/lib/connector/sabre/quotaplugin.php
+++ b/apps/dav/lib/connector/sabre/quotaplugin.php
@@ -120,12 +120,13 @@ public function getFileChunking($info) {
 	public function getLength() {
 		$req = $this->server->httpRequest;
 		$length = $req->getHeader('X-Expected-Entity-Length');
-		if (!$length) {
+		if (!is_numeric($length)) {
 			$length = $req->getHeader('Content-Length');
+			$length = is_numeric($length) ? $length : null;
 		}
 
 		$ocLength = $req->getHeader('OC-Total-Length');
-		if ($length && $ocLength) {
+		if (is_numeric($length) && is_numeric($ocLength)) {
 			return max($length, $ocLength);
 		}
 
diff --git a/apps/dav/tests/unit/connector/sabre/quotaplugin.php b/apps/dav/tests/unit/connector/sabre/quotaplugin.php
index 73a33331702ce..ef8598d914b95 100644
--- a/apps/dav/tests/unit/connector/sabre/quotaplugin.php
+++ b/apps/dav/tests/unit/connector/sabre/quotaplugin.php
@@ -130,6 +130,12 @@ public function lengthProvider() {
 			array(512, array('CONTENT-LENGTH' => '512')),
 			array(2048, array('OC-TOTAL-LENGTH' => '2048', 'CONTENT-LENGTH' => '1024')),
 			array(4096, array('OC-TOTAL-LENGTH' => '2048', 'X-EXPECTED-ENTITY-LENGTH' => '4096')),
+			[null, ['X-EXPECTED-ENTITY-LENGTH' => 'A']],
+			[null, ['CONTENT-LENGTH' => 'A']],
+			[1024, ['OC-TOTAL-LENGTH' => 'A', 'CONTENT-LENGTH' => '1024']],
+			[1024, ['OC-TOTAL-LENGTH' => 'A', 'X-EXPECTED-ENTITY-LENGTH' => '1024']],
+			[null, ['OC-TOTAL-LENGTH' => '2048', 'X-EXPECTED-ENTITY-LENGTH' => 'A']],
+			[null, ['OC-TOTAL-LENGTH' => '2048', 'CONTENT-LENGTH' => 'A']],
 		);
 	}