diff --git a/lib/private/Files/Storage/Wrapper/Quota.php b/lib/private/Files/Storage/Wrapper/Quota.php
index b0ff0117b960f..a7fd91b1f4c6a 100644
--- a/lib/private/Files/Storage/Wrapper/Quota.php
+++ b/lib/private/Files/Storage/Wrapper/Quota.php
@@ -230,7 +230,7 @@ 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, $size);
 			} else {
 				throw new NotEnoughSpaceException();
diff --git a/tests/lib/Files/Storage/Wrapper/QuotaTest.php b/tests/lib/Files/Storage/Wrapper/QuotaTest.php
index 150917b9dd9e9..875dfd7b992e1 100644
--- a/tests/lib/Files/Storage/Wrapper/QuotaTest.php
+++ b/tests/lib/Files/Storage/Wrapper/QuotaTest.php
@@ -13,6 +13,7 @@
 use OC\Files\Storage\Local;
 use OC\Files\Storage\Wrapper\Quota;
 use OCP\Files;
+use OCP\Files\FileInfo;
 use OCP\Files\NotEnoughSpaceException;
 use OCP\ITempManager;
 use OCP\Server;
@@ -134,6 +135,34 @@ public function testStreamCopyNotEnoughSpace(): void {
 		fclose($outputStream);
 	}
 
+	public function testWriteStreamWithUnlimitedFreeSpaceSucceeds(): void {
+		// object stores report SPACE_UNLIMITED for quota-exempt uploads/ paths
+		$storage = $this->getMockBuilder(Local::class)
+			->onlyMethods(['free_space'])
+			->setConstructorArgs([['datadir' => $this->tmpDir]])
+			->getMock();
+		$storage->method('free_space')->willReturn(FileInfo::SPACE_UNLIMITED);
+		$storage->mkdir('uploads');
+
+		$instance = new Quota(['storage' => $storage, 'quota' => 9]);
+
+		$stream = fopen('data://text/plain,foobar', 'r');
+		$this->assertEquals(6, $instance->writeStream('uploads/foo', $stream, 6));
+		fclose($stream);
+	}
+
+	public function testWriteStreamWithKnownSizeStillEnforcesQuota(): void {
+		$instance = $this->getLimitedStorage(9);
+
+		$stream = fopen('data://text/plain,foobarqwerty', 'r');
+		$this->expectException(NotEnoughSpaceException::class);
+		try {
+			$instance->writeStream('files/foo', $stream, 12);
+		} finally {
+			fclose($stream);
+		}
+	}
+
 	public function testReturnFalseWhenFopenFailed(): void {
 		$failStorage = $this->getMockBuilder(Local::class)
 			->onlyMethods(['fopen'])