diff --git a/src/Composer/Command/ConfigCommand.php b/src/Composer/Command/ConfigCommand.php
index 72c356b8b..f92079e77 100644
--- a/src/Composer/Command/ConfigCommand.php
+++ b/src/Composer/Command/ConfigCommand.php
@@ -237,6 +237,8 @@ EOT
             $this->config->merge(['config' => $this->authConfigFile->exists() ? $this->authConfigFile->read() : []], $this->authConfigFile->getPath());
         }
 
+        $this->getIO()->loadConfiguration($this->config);
+
         // List the configuration of the file settings
         if (true === $input->getOption('list')) {
             $this->listConfiguration($this->config->all(), $this->config->raw(), $output, null, $input->getOption('source'));
diff --git a/src/Composer/IO/BaseIO.php b/src/Composer/IO/BaseIO.php
index 43d6f66f9..710f5a108 100644
--- a/src/Composer/IO/BaseIO.php
+++ b/src/Composer/IO/BaseIO.php
@@ -128,6 +128,11 @@ abstract class BaseIO implements IOInterface
         }
 
         foreach ($githubOauth as $domain => $token) {
+            if ($domain !== 'github.com' && !in_array($domain, $config->get('github-domains'), true)) {
+                $this->debug($domain.' is not in the configured github-domains, adding it implicitly as authentication is configured for this domain');
+                $config->merge(['config' => ['github-domains' => array_merge($config->get('github-domains'), [$domain])]], 'implicit-due-to-auth');
+            }
+
             // allowed chars for GH tokens are from https://github.blog/changelog/2021-03-04-authentication-token-format-updates/
             // plus dots which were at some point used for GH app integration tokens
             if (!Preg::isMatch('{^[.A-Za-z0-9_]+$}', $token)) {
@@ -137,11 +142,21 @@ abstract class BaseIO implements IOInterface
         }
 
         foreach ($gitlabOauth as $domain => $token) {
+            if ($domain !== 'gitlab.com' && !in_array($domain, $config->get('gitlab-domains'), true)) {
+                $this->debug($domain.' is not in the configured gitlab-domains, adding it implicitly as authentication is configured for this domain');
+                $config->merge(['config' => ['gitlab-domains' => array_merge($config->get('gitlab-domains'), [$domain])]], 'implicit-due-to-auth');
+            }
+
             $token = is_array($token) ? $token["token"] : $token;
             $this->checkAndSetAuthentication($domain, $token, 'oauth2');
         }
 
         foreach ($gitlabToken as $domain => $token) {
+            if ($domain !== 'gitlab.com' && !in_array($domain, $config->get('gitlab-domains'), true)) {
+                $this->debug($domain.' is not in the configured gitlab-domains, adding it implicitly as authentication is configured for this domain');
+                $config->merge(['config' => ['gitlab-domains' => array_merge($config->get('gitlab-domains'), [$domain])]], 'implicit-due-to-auth');
+            }
+
             $username = is_array($token) ? $token["username"] : $token;
             $password = is_array($token) ? $token["token"] : 'private-token';
             $this->checkAndSetAuthentication($domain, $username, $password);