diff --git a/lib/private/Files/Storage/Wrapper/Quota.php b/lib/private/Files/Storage/Wrapper/Quota.php
index 11b992dbf9727..d41ff6ff0e958 100644
--- a/lib/private/Files/Storage/Wrapper/Quota.php
+++ b/lib/private/Files/Storage/Wrapper/Quota.php
@@ -229,7 +229,7 @@ public function writeStream(string $path, $stream, ?int $size = null): int {
 		}
 
 		if ($size !== null) {
-			if ($size < $free) {
+			if ($free < 0 || $size < $free) {
 				return parent::writeStream($path, $stream, $size);
 			} else {
 				throw new NotEnoughSpaceException();