diff --git a/src/hooks/diagnostics.ts b/src/hooks/diagnostics.ts
index 22c43ea6..7ec5b9c1 100644
--- a/src/hooks/diagnostics.ts
+++ b/src/hooks/diagnostics.ts
@@ -12,29 +12,37 @@ export const hook: HookFunction = (options) => Promise.all([registryCheck(option
 
 // eslint-disable-next-line @typescript-eslint/require-await
 const registryCheck = async (options: { doctor: SfDoctor }): Promise<void> => {
+  // find npm install
+  const npm = new NpmModule('');
+  const config = npm.run('config get registry').stdout.trim();
+  const customRegistry =
+    process.env.npm_config_registry ?? process.env.NPM_CONFIG_REGISTRY ?? config !== 'https://registry.npmjs.org/'
+      ? config
+      : undefined;
   // eslint-disable-next-line @typescript-eslint/no-floating-promises
   [
     // npm and yarn registries
     'https://registry.npmjs.org',
     'https://registry.yarnpkg.com',
-  ].map(async (url) => {
-    try {
-      // find npm install
-      const module = new NpmModule('');
+    customRegistry,
+  ]
+    // incase customRegistry is undefined, prevent printing an extra line
+    .filter((u) => u)
+    .map(async (url) => {
+      try {
+        const results = npm.ping(url);
 
-      const results = module.ping(url);
-
-      // timeout after 5000ms, error
-      if (!results || results.time > 5000) {
-        // to trigger the catch/fail below
-        throw Error;
+        // timeout after 5000ms, error
+        if (!results || results.time > 5000) {
+          // to trigger the catch/fail below
+          throw Error;
+        }
+        await Lifecycle.getInstance().emit('Doctor:diagnostic', { testName: `can access: ${url}`, status: 'pass' });
+      } catch (e) {
+        await Lifecycle.getInstance().emit('Doctor:diagnostic', { testName: `can't access: ${url}`, status: 'fail' });
+        options.doctor.addSuggestion(
+          `Cannot reach ${url} - potential network configuration error, check proxies, firewalls, environment variables`
+        );
       }
-      await Lifecycle.getInstance().emit('Doctor:diagnostic', { testName: `can access: ${url}`, status: 'pass' });
-    } catch (e) {
-      await Lifecycle.getInstance().emit('Doctor:diagnostic', { testName: `can't access: ${url}`, status: 'fail' });
-      options.doctor.addSuggestion(
-        `Cannot reach ${url} - potential network configuration error, check proxies, firewalls, environment variables`
-      );
-    }
-  });
+    });
 };
diff --git a/src/shared/npmCommand.ts b/src/shared/npmCommand.ts
index b38d85d7..ae5bf9fa 100644
--- a/src/shared/npmCommand.ts
+++ b/src/shared/npmCommand.ts
@@ -11,7 +11,7 @@ import { createRequire } from 'node:module';
 
 import fs from 'node:fs';
 import npmRunPath from 'npm-run-path';
-import shelljs from 'shelljs';
+import shelljs, { ShellString } from 'shelljs';
 import { SfError } from '@salesforce/core';
 import { sleep, parseJson } from '@salesforce/kit';
 import { Ux } from '@salesforce/sf-plugins-core';
@@ -165,6 +165,10 @@ export class NpmModule {
     };
   }
 
+  public run(command: string): ShellString {
+    return NpmCommand.runNpmCmd(command, { cliRoot: this.cliRoot, json: command.includes('--json') });
+  }
+
   public show(registry: string): NpmShowResults {
     const showCmd = NpmCommand.runNpmCmd(`show ${this.module}@${this.version} --json`, {
       registry,