diff --git a/src/ModernMT.php b/src/ModernMT.php
index 19b1994..188278c 100644
--- a/src/ModernMT.php
+++ b/src/ModernMT.php
@@ -94,6 +94,8 @@ public function translate($source, $target, $q, $hints = null, $context_vector =
                 $data['format'] = $options['format'];
             if (isset($options['alt_translations']))
                 $data['alt_translations'] = $options['alt_translations'];
+            if (isset($options['session']))
+                $data['session'] = $options['session'];
         }
 
         return $this->http->send('get', '/translate', $data);
@@ -125,6 +127,8 @@ public function batchTranslate($webhook, $source, $target, $q, $hints = null, $c
                 $data['alt_translations'] = $options['alt_translations'];
             if (isset($options['metadata']))
                 $data['metadata'] = $options['metadata'];
+            if (isset($options['session']))
+                $data['session'] = $options['session'];
 
             if (isset($options['idempotency_key']))
                 $headers = ["x-idempotency-key" => $options['idempotency_key']];
diff --git a/src/internal/MemoryServices.php b/src/internal/MemoryServices.php
index 036f67e..254c17b 100644
--- a/src/internal/MemoryServices.php
+++ b/src/internal/MemoryServices.php
@@ -66,26 +66,28 @@ public function delete($id) {
     /**
      * @throws ModernMTException
      */
-    public function add($memory, $source, $target, $sentence, $translation, $tuid = null) {
+    public function add($memory, $source, $target, $sentence, $translation, $tuid = null, $session = null) {
         return $this->http->send('post', "/memories/$memory/content", [
             'source' => $source,
             'target' => $target,
             'sentence' => $sentence,
             'translation' => $translation,
-            'tuid' => $tuid
+            'tuid' => $tuid,
+            'session' => $session
         ]);
     }
 
     /**
      * @throws ModernMTException
      */
-    public function replace($memory, $tuid, $source, $target, $sentence, $translation) {
+    public function replace($memory, $tuid, $source, $target, $sentence, $translation, $session = null) {
         return $this->http->send('put', "/memories/$memory/content", [
             'tuid' => $tuid,
             'source' => $source,
             'target' => $target,
             'sentence' => $sentence,
-            'translation' => $translation
+            'translation' => $translation,
+            'session' => $session
         ]);
     }