diff --git a/src/Credentials/ExternalAccountCredentials.php b/src/Credentials/ExternalAccountCredentials.php
index 478063be12..c0306ee807 100644
--- a/src/Credentials/ExternalAccountCredentials.php
+++ b/src/Credentials/ExternalAccountCredentials.php
@@ -52,6 +52,8 @@ class ExternalAccountCredentials implements
     private ?string $serviceAccountImpersonationUrl;
     private ?string $workforcePoolUserProject;
     private ?string $projectId;
+    /** @var array<mixed> */
+    private ?array $lastImpersonatedAccessToken;
     private string $universeDomain;
 
     /**
@@ -270,7 +272,10 @@ public function fetchAuthToken(?callable $httpHandler = null, array $headers = [
         $stsToken = $this->auth->fetchAuthToken($httpHandler, $headers);
 
         if (isset($this->serviceAccountImpersonationUrl)) {
-            return $this->getImpersonatedAccessToken($stsToken['access_token'], $httpHandler);
+            return $this->lastImpersonatedAccessToken = $this->getImpersonatedAccessToken(
+                $stsToken['access_token'],
+                $httpHandler
+            );
         }
 
         return $stsToken;
@@ -301,7 +306,7 @@ public function getCacheKey(): ?string
 
     public function getLastReceivedToken()
     {
-        return $this->auth->getLastReceivedToken();
+        return $this->lastImpersonatedAccessToken ?? $this->auth->getLastReceivedToken();
     }
 
     /**
diff --git a/tests/Credentials/ExternalAccountCredentialsTest.php b/tests/Credentials/ExternalAccountCredentialsTest.php
index 4d1f8ae0ed..3cade03037 100644
--- a/tests/Credentials/ExternalAccountCredentialsTest.php
+++ b/tests/Credentials/ExternalAccountCredentialsTest.php
@@ -293,7 +293,7 @@ public function testFetchAuthTokenWithImpersonation()
                     $this->assertEquals('service-account-impersonation-url.com', (string) $request->getUri());
                     $requestBody = json_decode((string) $request->getBody(), true);
                     $this->assertEquals(['a-scope'], $requestBody['scope']);
-                    $responseBody = json_encode(['accessToken' => 'def', 'expireTime' => $expiry]);
+                    $responseBody = json_encode(['accessToken' => 'ghi', 'expireTime' => $expiry]);
                     break;
             }
 
@@ -311,8 +311,11 @@ public function testFetchAuthTokenWithImpersonation()
 
         $authToken = $creds->fetchAuthToken($httpHandler);
         $this->assertArrayHasKey('access_token', $authToken);
-        $this->assertEquals('def', $authToken['access_token']);
+        $this->assertEquals('ghi', $authToken['access_token']);
         $this->assertEquals(strtotime($expiry), $authToken['expires_at']);
+
+        // test that getLastReceivedToken() returns the correct token
+        $this->assertEquals($authToken, $creds->getLastReceivedToken());
     }
 
     public function testGetQuotaProject()