diff --git a/packages/backend/src/misc/gen-key-pair.ts b/packages/backend/src/misc/gen-key-pair.ts
index 58e3091369..0b033ec33e 100644
--- a/packages/backend/src/misc/gen-key-pair.ts
+++ b/packages/backend/src/misc/gen-key-pair.ts
@@ -6,8 +6,7 @@
 import { genEd25519KeyPair, genRsaKeyPair } from '@misskey-dev/node-http-message-signatures';
 
 export async function genRSAAndEd25519KeyPair(rsaModulusLength = 4096) {
-	const rsa = await genRsaKeyPair(rsaModulusLength);
-	const ed25519 = await genEd25519KeyPair();
+	const [rsa, ed25519] = await Promise.all([genRsaKeyPair(rsaModulusLength), genEd25519KeyPair()]);
 	return {
 		publicKey: rsa.publicKey,
 		privateKey: rsa.privateKey,