diff --git a/google/refine/refine.py b/google/refine/refine.py
index 13a70af..7d87e86 100644
--- a/google/refine/refine.py
+++ b/google/refine/refine.py
@@ -285,7 +285,7 @@ class RefineProject:
 
     def wait_until_idle(self, polling_delay=0.5):
         while True:
-            response = self.do('get-processes')
+            response = self.do_json('get-processes')
             if 'processes' in response and len(response['processes']) > 0:
                 time.sleep(polling_delay)
             else:
@@ -293,7 +293,7 @@ class RefineProject:
 
     def apply_operations(self, file_path, wait=True):
         json = open(file_path).read()
-        response_json = self.do('apply-operations', {'operations': json})
+        response_json = self.do_json('apply-operations', {'operations': json})
         if response_json['code'] == 'pending' and wait:
             self.wait_until_idle()
             return 'ok'