diff --git a/core/modules/system/src/Tests/Module/InstallUninstallTest.php b/core/modules/system/src/Tests/Module/InstallUninstallTest.php
index d8d625b..0936b2e 100644
--- a/core/modules/system/src/Tests/Module/InstallUninstallTest.php
+++ b/core/modules/system/src/Tests/Module/InstallUninstallTest.php
@@ -4,6 +4,7 @@
 
 use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Core\Logger\RfcLogLevel;
+use Drupal\workspace\Entity\Workspace;
 
 /**
  * Install/uninstall core module and confirm table creation/deletion.
@@ -148,6 +149,12 @@ public function testInstallUninstall() {
         $this->preUninstallForum();
       }
 
+      // Delete all workspaces before uninstall.
+      if ($name == 'workspace') {
+        $workspaces = Workspace::loadMultiple();
+        \Drupal::entityTypeManager()->getStorage('workspace')->delete($workspaces);
+      }
+
       $now_installed_list = \Drupal::moduleHandler()->getModuleList();
       $added_modules = array_diff(array_keys($now_installed_list), array_keys($was_installed_list));
       while ($added_modules) {