diff --git a/CRM/Utils/Token.php b/CRM/Utils/Token.php
index 96e4598a4678..f2aec1d44e89 100644
--- a/CRM/Utils/Token.php
+++ b/CRM/Utils/Token.php
@@ -1633,10 +1633,13 @@ public static function replaceEntityTokens($entity, $entityArray, $str, $knownTo
    * @return string
    * @throws \CiviCRM_API3_Exception
    */
-  public static function replaceCaseTokens($caseId, $str, $knownTokens = [], $escapeSmarty = FALSE) {
-    if (!$knownTokens || empty($knownTokens['case'])) {
+  public static function replaceCaseTokens($caseId, $str, $knownTokens = NULL, $escapeSmarty = FALSE): string {
+    if (strpos($str, '{case.') === FALSE) {
       return $str;
     }
+    if (!$knownTokens) {
+      $knownTokens = self::getTokens($str);
+    }
     $case = civicrm_api3('case', 'getsingle', ['id' => $caseId]);
     return self::replaceEntityTokens('case', $case, $str, $knownTokens, $escapeSmarty);
   }
diff --git a/tests/phpunit/CRM/Utils/TokenConsistencyTest.php b/tests/phpunit/CRM/Utils/TokenConsistencyTest.php
new file mode 100644
index 000000000000..bae1d43e1ef6
--- /dev/null
+++ b/tests/phpunit/CRM/Utils/TokenConsistencyTest.php
@@ -0,0 +1,150 @@
+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ * CRM_Utils_TokenConsistencyTest
+ *
+ * Class for ensuring tokens have internal consistency.
+ *
+ * @group Tokens
+ *
+ * @group headless
+ */
+class CRM_Utils_TokenConsistencyTest extends CiviUnitTestCase {
+
+  use CRMTraits_Custom_CustomDataTrait;
+
+  /**
+   * Created case.
+   *
+   * @var array
+   */
+  protected $case;
+
+  /**
+   * Post test cleanup.
+   *
+   * @throws \API_Exception
+   * @throws \CRM_Core_Exception
+   */
+  public function tearDown(): void {
+    $this->quickCleanup(['civicrm_case', 'civicrm_case_type']);
+    parent::tearDown();
+  }
+
+  /**
+   * Test that case tokens are consistently rendered.
+   *
+   * @throws \API_Exception
+   * @throws \CiviCRM_API3_Exception
+   */
+  public function testCaseTokenConsistency(): void {
+    $this->createLoggedInUser();
+    CRM_Core_BAO_ConfigSetting::enableComponent('CiviCase');
+    $this->createCustomGroupWithFieldOfType(['extends' => 'Case']);
+    $tokens = CRM_Core_SelectValues::caseTokens();
+    $this->assertEquals($this->getCaseTokens(), $tokens);
+    $caseID = $this->getCaseID();
+    $tokenHtml = CRM_Utils_Token::replaceCaseTokens($caseID, implode("\n", array_keys($this->getCaseTokens())), ['case' => $this->getCaseTokenKeys()]);
+    $this->assertEquals($this->getExpectedCaseTokenOutput(), $tokenHtml);
+    // Now do the same without passing in 'knownTokens'
+    $tokenHtml = CRM_Utils_Token::replaceCaseTokens($caseID, implode("\n", array_keys($this->getCaseTokens())));
+    $this->assertEquals($this->getExpectedCaseTokenOutput(), $tokenHtml);
+  }
+
+  /**
+   * Get expected output from token parsing.
+   *
+   * @return string
+   */
+  protected function getExpectedCaseTokenOutput(): string {
+    return '1
+Housing Support
+Case Subject
+July 23rd, 2021
+July 26th, 2021
+case details
+Ongoing
+No
+' . $this->case['modified_date'] . '
+' . $this->case['created_date'] . '
+';
+  }
+
+  /**
+   * @return int
+   */
+  protected function getContactID(): int {
+    if (!isset($this->ids['Contact'][0])) {
+      $this->ids['Contact'][0] = $this->individualCreate();
+    }
+    return $this->ids['Contact'][0];
+  }
+
+  /**
+   * Get the keys for the case tokens.
+   *
+   * @return array
+   */
+  public function getCaseTokenKeys(): array {
+    $return = [];
+    foreach (array_keys($this->getCaseTokens()) as $key) {
+      $return[] = substr($key, 6, -1);
+    }
+    return $return;
+  }
+
+  /**
+   * Get declared tokens.
+   *
+   * @return string[]
+   */
+  public function getCaseTokens(): array {
+    return [
+      '{case.id}' => 'Case ID',
+      '{case.case_type_id}' => 'Case Type ID',
+      '{case.subject}' => 'Case Subject',
+      '{case.start_date}' => 'Case Start Date',
+      '{case.end_date}' => 'Case End Date',
+      '{case.details}' => 'Details',
+      '{case.status_id}' => 'Case Status',
+      '{case.is_deleted}' => 'Case is in the Trash',
+      '{case.created_date}' => 'Created Date',
+      '{case.modified_date}' => 'Modified Date',
+      '{case.custom_1}' => 'Enter text here :: Group with field text',
+    ];
+  }
+
+  /**
+   * Get case ID.
+   *
+   * @return int
+   */
+  protected function getCaseID(): int {
+    if (!isset($this->case)) {
+      $this->case = $this->callAPISuccess('Case', 'create', [
+        'case_type_id' => 'housing_support',
+        'activity_subject' => 'Case Subject',
+        'client_id' => $this->getContactID(),
+        'status_id' => 1,
+        'subject' => 'Case Subject',
+        'start_date' => '2021-07-23 15:39:20',
+        'end_date' => '2021-07-26 18:07:20',
+        'medium_id' => 2,
+        'details' => 'case details',
+        'activity_details' => 'blah blah',
+        'sequential' => 1,
+      ])['values'][0];
+    }
+    return $this->case['id'];
+  }
+
+}