diff --git a/os_performance_tools/collect.py b/os_performance_tools/collect.py
index dfae2f4..9add2f6 100644
--- a/os_performance_tools/collect.py
+++ b/os_performance_tools/collect.py
@@ -84,7 +84,7 @@ def main(argv=None, stdout=None):
         stdout.write(content)
         stdout.write(b"\n")
     if args.output:
-        with open(args.output, 'w') as output:
+        with open(args.output, 'wb') as output:
             output.write(content)
             output.write(b"\n")
 
diff --git a/os_performance_tools/tests/test_collect.py b/os_performance_tools/tests/test_collect.py
index 66c2f95..dbf0612 100644
--- a/os_performance_tools/tests/test_collect.py
+++ b/os_performance_tools/tests/test_collect.py
@@ -96,7 +96,7 @@ class TestCollect(base.TestCase):
             collect.main(
                 ['os-collect-counters', '--subunit', '--output', tfile.name],
                 self.stdout)
-            content = json.loads(tfile.read())
+            content = json.loads(tfile.read().decode('utf-8'))
             self.assertTrue(isinstance(content, dict))
             self.assertIn('mysql', content)
             self.assertIn('queues', content)