diff --git a/src/messageHandler.js b/src/messageHandler.js
index 365cdc3..4263616 100644
--- a/src/messageHandler.js
+++ b/src/messageHandler.js
@@ -20,7 +20,7 @@ const MERGE_PAGES = process.env.MERGE_PAGES !== 'false'
 async function mergePages(filePaths, dienstnummer) {
   const out = path.join(os.tmpdir(), `dienst-${dienstnummer}-${crypto.randomBytes(4).toString('hex')}.jpg`)
   try {
-    await execFileP(MAGICK_BIN, ['-append', ...filePaths, out])
+    await execFileP(MAGICK_BIN, [...filePaths, '-append', out])
     return out
   } catch (err) {
     console.error(`magick merge failed for ${dienstnummer}: ${err.message}`)