diff --git a/packages/backend/src/queue/processors/db/import-custom-emojis.ts b/packages/backend/src/queue/processors/db/import-custom-emojis.ts
index f2371429f2..33b68afd48 100644
--- a/packages/backend/src/queue/processors/db/import-custom-emojis.ts
+++ b/packages/backend/src/queue/processors/db/import-custom-emojis.ts
@@ -11,14 +11,28 @@ import { addFile } from "@/services/drive/add-file.js";
 import { genId } from "backend-rs";
 import { db } from "@/db/postgre.js";
 import probeImageSize from "probe-image-size";
-import * as path from "path";
+import * as path from "node:path";
 
 const logger = queueLogger.createSubLogger("import-custom-emojis");
 
+// probeImageSize acceptable extensions
+// JPG, GIF, PNG, WebP, BMP, TIFF, SVG, PSD.
+const acceptableExtensions = [
+	".jpeg",
+	".jpg",
+	".gif",
+	".png",
+	".webp",
+	".bmp",
+	// ".tiff", // Cannot be used as emoji
+	// ".svg", // Disable for secure issues
+	// ".psd", // Cannot be used as emoji
+];
+
 // TODO: 名前衝突時の動作を選べるようにする
 export async function importCustomEmojis(
 	job: Bull.Job<DbUserImportJobData>,
-	done: any,
+	done: () => void,
 ): Promise<void> {
 	logger.info("Importing custom emojis ...");
 
@@ -62,6 +76,14 @@ export async function importCustomEmojis(
 				if (!record.downloaded) continue;
 				const emojiInfo = record.emoji;
 				const emojiPath = `${outputPath}/${record.fileName}`;
+
+				const extname = path.extname(record.fileName);
+
+				// Skip non-support files
+				if (!acceptableExtensions.includes(extname.toLowerCase())) {
+					continue;
+				}
+
 				await Emojis.delete({
 					name: emojiInfo.name,
 				});
@@ -92,7 +114,7 @@ export async function importCustomEmojis(
 		} else {
 			logger.info("starting emoji import without metadata");
 			// Since we lack metadata, we import into a randomized category name instead
-			let categoryName = genId();
+			const categoryName = genId();
 
 			let containedEmojis = fs.readdirSync(outputPath);
 
@@ -103,7 +125,14 @@ export async function importCustomEmojis(
 
 			for (const emojiFilename of containedEmojis) {
 				// strip extension and get filename to use as name
-				const name = path.basename(emojiFilename, path.extname(emojiFilename));
+				const extname = path.extname(emojiFilename);
+
+				// Skip non-emoji files, such as LICENSE
+				if (!acceptableExtensions.includes(extname.toLowerCase())) {
+					continue;
+				}
+
+				const name = path.basename(emojiFilename, extname);
 				const emojiPath = `${outputPath}/${emojiFilename}`;
 
 				logger.info(`importing ${name}`);