diff --git a/src/lib/modules/file/upload.ts b/src/lib/modules/file/upload.ts
index 2c84f93..b5b00a1 100644
--- a/src/lib/modules/file/upload.ts
+++ b/src/lib/modules/file/upload.ts
@@ -110,7 +110,7 @@ const encryptFile = limitFunction(
 
     const thumbnail = await generateThumbnail(fileBuffer, fileType);
     const thumbnailBuffer = await thumbnail?.arrayBuffer();
-    const thumbnailEncrypted = thumbnailBuffer ? await encryptData(thumbnailBuffer, dataKey) : null;
+    const thumbnailEncrypted = thumbnailBuffer && (await encryptData(thumbnailBuffer, dataKey));
 
     status.update((value) => {
       value.status = "upload-pending";
@@ -126,8 +126,7 @@ const encryptFile = limitFunction(
       nameEncrypted,
       createdAtEncrypted,
       lastModifiedAtEncrypted,
-      thumbnail: thumbnail &&
-        thumbnailEncrypted && { plaintext: thumbnailBuffer, ...thumbnailEncrypted },
+      thumbnail: thumbnailEncrypted && { plaintext: thumbnailBuffer, ...thumbnailEncrypted },
     };
   },
   { concurrency: 4 },
diff --git a/src/routes/(fullscreen)/settings/thumbnails/+page.svelte b/src/routes/(fullscreen)/settings/thumbnails/+page.svelte
index 68c6d6f..d9cd692 100644
--- a/src/routes/(fullscreen)/settings/thumbnails/+page.svelte
+++ b/src/routes/(fullscreen)/settings/thumbnails/+page.svelte
@@ -43,7 +43,7 @@
 <TopBar title="썸네일" />
 <FullscreenDiv class="bg-gray-100 !px-0">
   <div class="flex flex-grow flex-col space-y-4">
-    <div class="flex-shrink-0 bg-white p-4 !pt-0">
+    <div class="bg-white p-4 !pt-0">
       <IconEntryButton icon={IconDelete} onclick={deleteAllFileThumbnailCaches} class="w-full">
         저장된 썸네일 모두 삭제하기
       </IconEntryButton>
@@ -70,7 +70,7 @@
     {/if}
   </div>
   {#if persistentStates.files.length > 0}
-    <BottomDiv class="flex flex-col items-center gap-y-2 px-4">
+    <BottomDiv class="px-4">
       <Button onclick={generateAllThumbnails} class="w-full">모두 썸네일 생성하기</Button>
     </BottomDiv>
   {/if}
diff --git a/src/routes/(fullscreen)/settings/thumbnails/service.svelte.ts b/src/routes/(fullscreen)/settings/thumbnails/service.svelte.ts
index aaee616..59e35f4 100644
--- a/src/routes/(fullscreen)/settings/thumbnails/service.svelte.ts
+++ b/src/routes/(fullscreen)/settings/thumbnails/service.svelte.ts
@@ -27,7 +27,7 @@ export const persistentStates = $state({
   files: [] as File[],
 });
 
-export const getGenerationStatus = (fileId: number): Writable<GenerationStatus> | undefined => {
+export const getGenerationStatus = (fileId: number) => {
   return workingFiles.get(fileId);
 };
 
@@ -39,6 +39,7 @@ const generateThumbnail = limitFunction(
     dataKey: CryptoKey,
   ) => {
     status.set("generating");
+
     const thumbnail = await doGenerateThumbnail(fileBuffer, fileType);
     if (!thumbnail) {
       status.set("error");
@@ -47,7 +48,6 @@ const generateThumbnail = limitFunction(
 
     const thumbnailBuffer = await thumbnail.arrayBuffer();
     const thumbnailEncrypted = await encryptData(thumbnailBuffer, dataKey);
-
     status.set("upload-pending");
     return { plaintext: thumbnailBuffer, ...thumbnailEncrypted };
   },