diff --git a/lib/Capabilities.php b/lib/Capabilities.php
index 6db67c301a..243ca7d0be 100644
--- a/lib/Capabilities.php
+++ b/lib/Capabilities.php
@@ -9,6 +9,7 @@
 namespace OCA\Richdocuments;
 
 use OCA\Richdocuments\Service\CapabilitiesService;
+use OCA\Richdocuments\Service\DiscoveryService;
 use OCP\App\IAppManager;
 use OCP\Capabilities\ICapability;
 use OCP\IURLGenerator;
@@ -97,6 +98,7 @@ public function __construct(
 		private IAppManager $appManager,
 		private ?string $userId,
 		private IURLGenerator $urlGenerator,
+		private DiscoveryService $discoveryService,
 	) {
 	}
 
@@ -141,7 +143,7 @@ public function getCapabilities() {
 	 * @return list<string>
 	 */
 	public function getDefaultMimetypes(): array {
-		$defaultMimetypes = self::MIMETYPES;
+		$defaultMimetypes = $this->discoveryService->getSupportedMimeTypes() ?: self::MIMETYPES;
 
 		if (!$this->capabilitiesService->hasOtherOOXMLApps()) {
 			array_push($defaultMimetypes, ...self::MIMETYPES_MSOFFICE);
@@ -151,7 +153,7 @@ public function getDefaultMimetypes(): array {
 			$defaultMimetypes[] = 'application/pdf';
 		}
 
-		return $defaultMimetypes;
+		return array_values(array_unique($defaultMimetypes));
 	}
 
 	/**
diff --git a/lib/Service/DiscoveryService.php b/lib/Service/DiscoveryService.php
index 9a001b39a8..6b47620bc0 100644
--- a/lib/Service/DiscoveryService.php
+++ b/lib/Service/DiscoveryService.php
@@ -127,4 +127,34 @@ private function getParsed(): SimpleXMLElement {
 			throw new \Exception('Could not parse discovery XML');
 		}
 	}
+
+	/**
+	 * Dynamically get all supported mime types out of the discovery XML
+	 * @todo Currently no categories given from endpoint
+	 *
+	 * @return array
+	 * @throws \Exception
+	 */
+	public function getSupportedMimeTypes(): array {
+		$mimeTypes = [];
+
+		try {
+			$parsed = $this->getParsed();
+		} catch (\Exception $e) {
+			// @todo fallback to a default set instead of empty array
+			return $mimeTypes;
+		}
+
+		foreach ($parsed->xpath('//net-zone/app') as $app) {
+			$mimeTypeName = (string)$app['name']; // (e.g. "application/pdf")
+
+			// Filter (Settings, Capabilities, etc.)
+			if (!str_contains($mimeTypeName, '/')) {
+				continue;
+			}
+			$mimeTypes[] = $mimeTypeName;
+		}
+
+		return array_values(array_unique($mimeTypes));
+	}
 }