diff --git a/lib/Service/AttachmentService.php b/lib/Service/AttachmentService.php
index 2373dfb0a47..a7b213c2e78 100755
--- a/lib/Service/AttachmentService.php
+++ b/lib/Service/AttachmentService.php
@@ -284,6 +284,11 @@ public function uploadAttachment(int $documentId, string $newFileName, $newFileR
 			throw new NotPermittedException('No write permissions');
 		}
 		$saveDir = $this->getAttachmentDirectoryForFile($textFile, true);
+		// The filecache stores names in Unicode NFC, while uploads from macOS may use NFD
+		$normalizedFileName = \Normalizer::normalize($newFileName, \Normalizer::FORM_C);
+		if ($normalizedFileName !== false) {
+			$newFileName = $normalizedFileName;
+		}
 		$fileName = self::getUniqueFileName($saveDir, $newFileName);
 		$this->filenameValidator->validateFilename($fileName);
 		$savedFile = $saveDir->newFile($fileName, $newFileResource);
diff --git a/src/services/AttachmentResolver.js b/src/services/AttachmentResolver.js
index 48f9ce921b0..06b7a2fbe6d 100644
--- a/src/services/AttachmentResolver.js
+++ b/src/services/AttachmentResolver.js
@@ -36,7 +36,11 @@ export default class AttachmentResolver {
 	}
 
 	#findAttachment(fileName) {
-		return this.#attachmentList.find((a) => a.name === fileName)
+		// Attachment srcs may use NFD (e.g. uploads from macOS), the attachment list uses NFC
+		const normalizedName = fileName.normalize('NFC')
+		return this.#attachmentList.find(
+			(a) => a.name.normalize('NFC') === normalizedName,
+		)
 	}
 
 	/*
diff --git a/src/tests/services/AttachmentResolver.spec.js b/src/tests/services/AttachmentResolver.spec.js
index f1593201a39..b665bf7cc25 100644
--- a/src/tests/services/AttachmentResolver.spec.js
+++ b/src/tests/services/AttachmentResolver.spec.js
@@ -100,4 +100,25 @@ describe('Image resolver', () => {
 			'http://localhost:3000/remote.php/dav/files/user-uid/parentDir/path/to/some%20image.png',
 		)
 	})
+
+	it('matches attachment names regardless of Unicode normalization', async () => {
+		const nfcName = 'B\u00FCcher.pdf'
+		const nfdName = 'Bu\u0308cher.pdf'
+		vi.spyOn(axios, 'post').mockReturnValue({
+			data: [
+				{
+					fileId: 1237,
+					name: nfcName,
+					mimetype: 'application/pdf',
+					isImage: false,
+				},
+			],
+		})
+		const resolver = new AttachmentResolver({ session })
+		const attachment = await resolver.resolve(
+			`.attachments.${session.documentId}/${encodeURIComponent(nfdName)}`,
+		)
+		expect(attachment.isImage).toBe(false)
+		expect(attachment.name).toBe(nfcName)
+	})
 })