diff --git a/packages/backend/src/core/HttpRequestService.ts b/packages/backend/src/core/HttpRequestService.ts
index 60ecc03e4a..8a6d978232 100644
--- a/packages/backend/src/core/HttpRequestService.ts
+++ b/packages/backend/src/core/HttpRequestService.ts
@@ -27,21 +27,11 @@ export type HttpRequestSendOptions = {
 
 @Injectable()
 export class HttpRequestService {
-	/**
-	 * Get http non-proxy agent
-	 */
-	private http: http.Agent;
-
 	/**
 	 * Get https non-proxy agent
 	 */
 	private https: https.Agent;
 
-	/**
-	 * Get http proxy or non-proxy agent
-	 */
-	public httpAgent: http.Agent;
-
 	/**
 	 * Get https proxy or non-proxy agent
 	 */
@@ -57,34 +47,16 @@ export class HttpRequestService {
 			lookup: false,	// nativeのdns.lookupにfallbackしない
 		});
 
-		this.http = new http.Agent({
-			keepAlive: true,
-			keepAliveMsecs: 30 * 1000,
-			lookup: cache.lookup as unknown as net.LookupFunction,
-			localAddress: config.outgoingAddress,
-		});
-
 		this.https = new https.Agent({
 			keepAlive: true,
 			keepAliveMsecs: 30 * 1000,
 			lookup: cache.lookup as unknown as net.LookupFunction,
 			localAddress: config.outgoingAddress,
+			minVersion: 'TLSv1.2',
 		});
 
 		const maxSockets = Math.max(256, config.deliverJobConcurrency ?? 128);
 
-		this.httpAgent = config.proxy
-			? new HttpProxyAgent({
-				keepAlive: true,
-				keepAliveMsecs: 30 * 1000,
-				maxSockets,
-				maxFreeSockets: 256,
-				scheduling: 'lifo',
-				proxy: config.proxy,
-				localAddress: config.outgoingAddress,
-			})
-			: this.http;
-
 		this.httpsAgent = config.proxy
 			? new HttpsProxyAgent({
 				keepAlive: true,
@@ -104,11 +76,17 @@ export class HttpRequestService {
 	 * @param bypassProxy Allways bypass proxy
 	 */
 	@bindThis
-	public getAgentByUrl(url: URL, bypassProxy = false): http.Agent | https.Agent {
+	public getAgentByUrl(url: URL, bypassProxy = false): https.Agent {
+		if (url.protocol !== 'https:') {
+			throw new Error('Invalid protocol');
+		}
+		if (url.port && url.port !== '443') {
+			throw new Error('Invalid port');
+		}
 		if (bypassProxy || (this.config.proxyBypassHosts ?? []).includes(url.hostname)) {
-			return url.protocol === 'http:' ? this.http : this.https;
+			return this.https;
 		} else {
-			return url.protocol === 'http:' ? this.httpAgent : this.httpsAgent;
+			return this.httpsAgent;
 		}
 	}