diff --git a/src/Core/CHANGELOG.md b/src/Core/CHANGELOG.md
index a094064f5..f1537ed4e 100644
--- a/src/Core/CHANGELOG.md
+++ b/src/Core/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 ## NOT RELEASED
 
+## 1.24.1
+
+### Fixed
+
+- Better detection and error messages for when SSO is used but required packages are not installed.
+
 ## 1.24.0
 
 ### Added
diff --git a/src/Core/src/Credentials/IniFileProvider.php b/src/Core/src/Credentials/IniFileProvider.php
index 2caab8ee3..5d13512ed 100644
--- a/src/Core/src/Credentials/IniFileProvider.php
+++ b/src/Core/src/Credentials/IniFileProvider.php
@@ -8,6 +8,7 @@
 use AsyncAws\Core\Exception\RuntimeException;
 use AsyncAws\Core\Sts\StsClient;
 use AsyncAws\Sso\SsoClient;
+use AsyncAws\SsoOidc\SsoOidcClient;
 use Psr\Log\LoggerInterface;
 use Psr\Log\NullLogger;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -94,8 +95,8 @@ private function getCredentialsFromProfile(array $profilesData, string $profile,
         }
 
         if (isset($profileData[IniFileLoader::KEY_SSO_SESSION])) {
-            if (!class_exists(SsoClient::class)) {
-                $this->logger->warning('The profile "{profile}" contains SSO session config but the "async-aws/sso" package is not installed. Try running "composer require async-aws/sso".', ['profile' => $profile]);
+            if (!class_exists(SsoClient::class) || !class_exists(SsoOidcClient::class)) {
+                $this->logger->warning('The profile "{profile}" contains SSO session config but the required packages ("async-aws/sso" and "async-aws/sso-oidc") are not installed. Try running "composer require async-aws/sso async-aws/sso-oidc".', ['profile' => $profile]);
 
                 return null;
             }
@@ -104,7 +105,7 @@ private function getCredentialsFromProfile(array $profilesData, string $profile,
         }
 
         if (isset($profileData[IniFileLoader::KEY_SSO_START_URL])) {
-            if (class_exists(SsoClient::class)) {
+            if (!class_exists(SsoClient::class)) {
                 $this->logger->warning('The profile "{profile}" contains SSO (legacy) config but the "async-aws/sso" package is not installed. Try running "composer require async-aws/sso".', ['profile' => $profile]);
 
                 return null;