diff --git a/module/Core/test/Action/QrCodeActionTest.php b/module/Core/test/Action/QrCodeActionTest.php
index eb68f0e1..236288dd 100644
--- a/module/Core/test/Action/QrCodeActionTest.php
+++ b/module/Core/test/Action/QrCodeActionTest.php
@@ -81,4 +81,30 @@ class QrCodeActionTest extends TestCase
         $this->assertEquals(200, $resp->getStatusCode());
         $delegate->handle(Argument::any())->shouldHaveBeenCalledTimes(0);
     }
+
+    /**
+     * @test
+     * @dataProvider provideQueries
+     */
+    public function imageIsReturnedWithExpectedContentTypeBasedOnProvidedFormat(
+        array $query,
+        string $expectedContentType
+    ): void {
+        $code = 'abc123';
+        $this->urlResolver->resolveEnabledShortUrl(new ShortUrlIdentifier($code, ''))->willReturn(new ShortUrl(''));
+        $delegate = $this->prophesize(RequestHandlerInterface::class);
+        $req = (new ServerRequest())->withAttribute('shortCode', $code)->withQueryParams($query);
+
+        $resp = $this->action->process($req, $delegate->reveal());
+
+        $this->assertEquals($expectedContentType, $resp->getHeaderLine('Content-Type'));
+    }
+
+    public function provideQueries(): iterable
+    {
+        yield 'no format' => [[], 'image/png'];
+        yield 'png format' => [['format' => 'png'], 'image/png'];
+        yield 'svg format' => [['format' => 'svg'], 'image/svg+xml'];
+        yield 'unsupported format' => [['format' => 'jpg'], 'image/png'];
+    }
 }