diff --git a/nullptr/api.py b/nullptr/api.py
index 440e33c..655663b 100644
--- a/nullptr/api.py
+++ b/nullptr/api.py
@@ -239,10 +239,12 @@ class Api:
 
   def extract(self, ship, survey=None):
     data = {}
+    url = f'my/ships/{ship}/extract'
     if survey is not None:
       data['survey'] = survey.api_dict()
+      url += '/survey'
     try:
-      data =  self.request('post', f'my/ships/{ship}/extract', data=data)
+      data =  self.request('post', url, data=data)
     except ApiError as e:
       if e.code in [ 4221, 4224]:
         survey.exhausted = True