Correctly compare version type.
diff --git a/jinja2/bccache.py b/jinja2/bccache.py
index 6638bbb..e53783b 100644
--- a/jinja2/bccache.py
+++ b/jinja2/bccache.py
@@ -28,7 +28,7 @@
 
 
 # marshal works better on 3.x, one hack less required
-if sys.version_info[0] > 3:
+if sys.version_info[0] >= 3:
     from io import BytesIO
     marshal_dump = marshal.dump
     marshal_load = marshal.load