diff --git a/packages/backend/src/remote/activitypub/models/person.ts b/packages/backend/src/remote/activitypub/models/person.ts
index bfc613523b..cd9da3390c 100644
--- a/packages/backend/src/remote/activitypub/models/person.ts
+++ b/packages/backend/src/remote/activitypub/models/person.ts
@@ -57,15 +57,15 @@ function validateActor(x: IObject, uri: string): IActor {
 		if (e) throw new Error(`invalid Actor: ${name} ${e.message}`);
 	};
 
-	validate('id', x.id, $.str.min(1));
-	validate('inbox', x.inbox, $.str.min(1));
-	validate('preferredUsername', x.preferredUsername, $.str.min(1).max(128).match(/^\w([\w-.]*\w)?$/));
+	validate('id', x.id, $.default.str.min(1));
+	validate('inbox', x.inbox, $.default.str.min(1));
+	validate('preferredUsername', x.preferredUsername, $.default.str.min(1).max(128).match(/^\w([\w-.]*\w)?$/));
 
 	// These fields are only informational, and some AP software allows these
 	// fields to be very long. If they are too long, we cut them off. This way
 	// we can at least see these users and their activities.
-	validate('name', truncate(x.name, nameLength), $.optional.nullable.str);
-	validate('summary', truncate(x.summary, summaryLength), $.optional.nullable.str);
+	validate('name', truncate(x.name, nameLength), $.default.optional.nullable.str);
+	validate('summary', truncate(x.summary, summaryLength), $.default.optional.nullable.str);
 
 	const idHost = toPuny(new URL(x.id!).hostname);
 	if (idHost !== expectHost) {
diff --git a/packages/backend/src/remote/resolve-user.ts b/packages/backend/src/remote/resolve-user.ts
index 8cbf02e68d..aa37013c4a 100644
--- a/packages/backend/src/remote/resolve-user.ts
+++ b/packages/backend/src/remote/resolve-user.ts
@@ -26,7 +26,7 @@ export async function resolveUser(username: string, host: string | null, option?
 
 	host = toPuny(host);
 
-	if (config.host == host) {
+	if (config.host === host) {
 		logger.info(`return local user: ${usernameLower}`);
 		return await Users.findOne({ usernameLower, host: null }).then(u => {
 			if (u == null) {
diff --git a/packages/backend/src/server/activitypub/followers.ts b/packages/backend/src/server/activitypub/followers.ts
index 644ecaf8c8..5d1d7c59eb 100644
--- a/packages/backend/src/server/activitypub/followers.ts
+++ b/packages/backend/src/server/activitypub/followers.ts
@@ -15,10 +15,10 @@ export default async (ctx: Router.RouterContext) => {
 	const userId = ctx.params.user;
 
 	// Get 'cursor' parameter
-	const [cursor, cursorErr] = $.optional.type(ID).get(ctx.request.query.cursor);
+	const [cursor, cursorErr] = $.default.optional.type(ID).get(ctx.request.query.cursor);
 
 	// Get 'page' parameter
-	const pageErr = !$.optional.str.or(['true', 'false']).ok(ctx.request.query.page);
+	const pageErr = !$.default.optional.str.or(['true', 'false']).ok(ctx.request.query.page);
 	const page: boolean = ctx.request.query.page === 'true';
 
 	// Validate parameters
diff --git a/packages/backend/src/server/activitypub/following.ts b/packages/backend/src/server/activitypub/following.ts
index b1f3f9ac7f..23110ce873 100644
--- a/packages/backend/src/server/activitypub/following.ts
+++ b/packages/backend/src/server/activitypub/following.ts
@@ -16,10 +16,10 @@ export default async (ctx: Router.RouterContext) => {
 	const userId = ctx.params.user;
 
 	// Get 'cursor' parameter
-	const [cursor, cursorErr] = $.optional.type(ID).get(ctx.request.query.cursor);
+	const [cursor, cursorErr] = $.default.optional.type(ID).get(ctx.request.query.cursor);
 
 	// Get 'page' parameter
-	const pageErr = !$.optional.str.or(['true', 'false']).ok(ctx.request.query.page);
+	const pageErr = !$.default.optional.str.or(['true', 'false']).ok(ctx.request.query.page);
 	const page: boolean = ctx.request.query.page === 'true';
 
 	// Validate parameters
diff --git a/packages/backend/src/server/activitypub/outbox.ts b/packages/backend/src/server/activitypub/outbox.ts
index 525ac81b97..57c126752a 100644
--- a/packages/backend/src/server/activitypub/outbox.ts
+++ b/packages/backend/src/server/activitypub/outbox.ts
@@ -20,13 +20,13 @@ export default async (ctx: Router.RouterContext) => {
 	const userId = ctx.params.user;
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $.optional.type(ID).get(ctx.request.query.since_id);
+	const [sinceId, sinceIdErr] = $.default.optional.type(ID).get(ctx.request.query.since_id);
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $.optional.type(ID).get(ctx.request.query.until_id);
+	const [untilId, untilIdErr] = $.default.optional.type(ID).get(ctx.request.query.until_id);
 
 	// Get 'page' parameter
-	const pageErr = !$.optional.str.or(['true', 'false']).ok(ctx.request.query.page);
+	const pageErr = !$.default.optional.str.or(['true', 'false']).ok(ctx.request.query.page);
 	const page: boolean = ctx.request.query.page === 'true';
 
 	// Validate parameters