diff --git a/tests/test_api_client.py b/tests/test_api_client.py
index b00ce3af9..a1b35cbde 100644
--- a/tests/test_api_client.py
+++ b/tests/test_api_client.py
@@ -196,7 +196,7 @@ class APIClientTests(APITestCase):
         schema = client.get('http://api.example.com/')
 
         temp = tempfile.NamedTemporaryFile()
-        temp.write('example file contents')
+        temp.write(b'example file contents')
         temp.flush()
 
         with open(temp.name, 'rb') as upload:
@@ -230,7 +230,7 @@ class APIClientTests(APITestCase):
         schema = client.get('http://api.example.com/')
 
         temp = tempfile.NamedTemporaryFile()
-        temp.write('example file contents')
+        temp.write(b'example file contents')
         temp.flush()
 
         with open(temp.name, 'rb') as upload: