diff --git a/googleapiclient/http.py b/googleapiclient/http.py
index 3959d81..733a12a 100644
--- a/googleapiclient/http.py
+++ b/googleapiclient/http.py
@@ -559,6 +559,8 @@
         content_range = resp['content-range']
         length = content_range.rsplit('/', 1)[1]
         self._total_size = int(length)
+      else:
+        self._total_size = int(resp['content-length'])
 
       if self._progress == self._total_size:
         self._done = True