diff --git a/Classes/Service/ImpersonateService.php b/Classes/Service/ImpersonateService.php
index cd85cc8..9751dc3 100644
--- a/Classes/Service/ImpersonateService.php
+++ b/Classes/Service/ImpersonateService.php
@@ -57,49 +57,75 @@ class ImpersonateService
     public function impersonate($account): void
     {
         $currentAccount = $this->securityContext->getAccount();
-        $this->session->putData('OriginalIdentity', $this->persistenceManager->getIdentifierByObject($currentAccount));
+        $this->writeSession('OriginalIdentity', $this->persistenceManager->getIdentifierByObject($currentAccount));
 
         $this->refreshTokens($account);
 
-        $this->session->putData('Impersonate', $this->persistenceManager->getIdentifierByObject($account));
+        $this->writeSession('Impersonate', $this->persistenceManager->getIdentifierByObject($account));
     }
 
+    /**
+     * @return void
+     * @throws SessionNotStartedException
+     */
     public function restoreOriginalIdentity(): void
     {
         $account = $this->getOriginalIdentity();
         $this->refreshTokens($account);
-        $this->session->putData('Impersonate', null);
+        $this->writeSession('Impersonate', null);
     }
 
+    /**
+     * @return Account|null
+     * @throws SessionNotStartedException
+     */
     public function getImpersonation(): ?Account
     {
-        if ($this->session->getData('Impersonate') !== null) {
-            return $this->persistenceManager->getObjectByIdentifier($this->session->getData('Impersonate'), Account::class);
+        $impersonation = $this->getSessionData('Impersonate');
+        if ($impersonation !== null) {
+            return $this->persistenceManager->getObjectByIdentifier($impersonation, Account::class);
         }
         return null;
     }
 
+    /**
+     * @return bool
+     * @throws SessionNotStartedException
+     */
     public function isActive()
     {
         return $this->getImpersonation() instanceof Account;
     }
 
+    /**
+     * @return Account|null
+     */
     public function getCurrentUser(): ?Account
     {
         return $this->securityContext->getAccount();
     }
 
+    /**
+     * @return Account|null
+     * @throws SessionNotStartedException
+     */
     public function getOriginalIdentity(): ?Account
     {
-        if ($this->session->getData('OriginalIdentity') !== null) {
-            return $this->persistenceManager->getObjectByIdentifier($this->session->getData('OriginalIdentity'), Account::class);
+        $originalIdentity = $this->getSessionData('OriginalIdentity');
+        if ($originalIdentity !== null) {
+            return $this->persistenceManager->getObjectByIdentifier($originalIdentity, Account::class);
         }
         return $this->securityContext->getAccount();
     }
 
+    /**
+     * @return array
+     * @throws SessionNotStartedException
+     */
     public function getOriginalIdentityRoles(): array
     {
-        $roles = $this->getOriginalIdentity()->getRoles();
+        $originalAccount = $this->getOriginalIdentity();
+        $roles = $originalAccount ? $originalAccount->getRoles() : [];
         foreach ($roles as $role) {
             foreach ($this->policyService->getAllParentRoles($role) as $parentRole) {
                 if (!in_array($parentRole, $roles)) {
@@ -110,6 +136,10 @@ public function getOriginalIdentityRoles(): array
         return $roles;
     }
 
+    /**
+     * @param Account|null $account
+     * @return void
+     */
     protected function refreshTokens(Account $account = null)
     {
         if ($account === null) {
@@ -121,4 +151,26 @@ protected function refreshTokens(Account $account = null)
             $token->setAccount($account);
         }
     }
+
+    /**
+     * @param string $key
+     * @param string|null $value
+     * @return void
+     * @throws SessionNotStartedException
+     */
+    protected function writeSession(string $key, ?string $value): void
+    {
+        if ($this->session->isStarted()) {
+            $this->session->putData($key, $value);
+        }
+    }
+
+    /**
+     * @param string $key
+     * @throws SessionNotStartedException
+     */
+    protected function getSessionData(string $key): mixed
+    {
+        return $this->session->isStarted() && $this->session->hasKey($key) ? $this->session->getData($key) : null;
+    }
 }