diff --git a/scripts/cluster.py b/scripts/cluster.py
index ccd379b5b..59a27e339 100644
--- a/scripts/cluster.py
+++ b/scripts/cluster.py
@@ -165,7 +165,7 @@ class RayCluster(object):
       start_workers_command = """
         cd "{}";
         source ../setup-env.sh;
-        python -c "import ray; ray.services.start_node(\\\"{}:10001\\\", \\\"{}\\\", {}, user_source_directory=\\\"{}\\\")" > start_workers.out 2> start_workers.err < /dev/null &
+        python -c "import ray; ray.services.start_node(\\\"{}:10001\\\", \\\"{}\\\", {}, user_source_directory={})" > start_workers.out 2> start_workers.err < /dev/null &
       """.format(scripts_directory, self.node_private_ip_addresses[0], self.node_private_ip_addresses[i], num_workers_per_node, remote_user_source_directory_str)
       start_workers_commands.append(start_workers_command)
     self._run_command_over_ssh_on_all_nodes_in_parallel(start_workers_commands)
@@ -213,8 +213,8 @@ class RayCluster(object):
     change_branch_command = "git checkout -f {}".format(branch) if branch is not None else ""
     update_cluster_command = """
       cd "{}" &&
-      {}
       git fetch &&
+      {}
       git reset --hard "@{{upstream}}" -- &&
       (make -C "./build" clean || rm -rf "./build") &&
       ./build.sh
@@ -244,7 +244,7 @@ class RayCluster(object):
       raise Exception("Directory {} does not exist.".format(user_source_directory))
     # If user_source_directory is "/a/b/c", then local_directory_name is "c".
     local_directory_name = os.path.split(os.path.realpath(user_source_directory))[1]
-    remote_directory = os.path.join("user_source_files", local_directory_name)
+    remote_directory = os.path.join(self.installation_directory, "user_source_files", local_directory_name)
     # Remove and recreate the directory on the node.
     recreate_directory_command = """
       rm -r "{}";
@@ -298,10 +298,9 @@ if __name__ == "__main__":
   args = parser.parse_args()
   username = args.username
   key_file = args.key_file
-  # Install Ray in the user's home directory on the cluster.
-  installation_directory = "$HOME"
   node_ip_addresses = []
   node_private_ip_addresses = []
+  # Check if the IP addresses in the nodes file are valid.
   for line in open(args.nodes).readlines():
     parts = line.split(",")
     ip_address = str(parts[0].strip())
@@ -313,5 +312,14 @@ if __name__ == "__main__":
       raise Exception("Each line in the nodes file must have either one or two ip addresses.")
     node_ip_addresses.append(ip_address)
     node_private_ip_addresses.append(private_ip_address)
+  # This command finds the home directory on the cluster. That directory will be
+  # used for installing Ray. Note that single quotes around 'echo $HOME' are
+  # important. If you use double quotes, then the $HOME environment variable
+  # will be expanded locally instead of remotely.
+  echo_home_command = "ssh -i {} {}@{} 'echo $HOME'".format(key_file, username, node_ip_addresses[0])
+  installation_directory = subprocess.check_output(echo_home_command, shell=True).strip()
+  print "Using '{}' as the home directory on the cluster.".format(installation_directory)
+  # Create the Raycluster object.
   cluster = RayCluster(node_ip_addresses, node_private_ip_addresses, username, key_file, installation_directory)
+  # Drop into an IPython shell.
   IPython.embed()