diff --git a/hail/python/hail/context.py b/hail/python/hail/context.py
index 1055c802b7b3..77493ecd0835 100644
--- a/hail/python/hail/context.py
+++ b/hail/python/hail/context.py
@@ -573,7 +573,7 @@ async def init_batch(
 
     log = _get_log(log)
     if tmpdir is None:
-        tmpdir = backend.remote_tmpdir + '/tmp/hail/' + secret_alnum_string()
+        tmpdir = os.path.join(backend.remote_tmpdir, 'tmp/hail', secret_alnum_string())
     local_tmpdir = _get_local_tmpdir(local_tmpdir)
 
     HailContext.create(log, quiet, append, tmpdir, local_tmpdir, default_reference, global_seed, backend)
diff --git a/hail/src/main/scala/is/hail/backend/Backend.scala b/hail/src/main/scala/is/hail/backend/Backend.scala
index e0444e371e27..329ee1a3e383 100644
--- a/hail/src/main/scala/is/hail/backend/Backend.scala
+++ b/hail/src/main/scala/is/hail/backend/Backend.scala
@@ -123,8 +123,6 @@ abstract class Backend extends Closeable {
     f: (Array[Byte], HailTaskContext, HailClassLoader, FS) => Array[Byte]
   ): (Option[Throwable], IndexedSeq[(Array[Byte], Int)])
 
-  def close(): Unit
-
   def asSpark(op: String): SparkBackend =
     fatal(s"${getClass.getSimpleName}: $op requires SparkBackend")