diff --git a/swh/search/tests/conftest.py b/swh/search/tests/conftest.py
index 62de0a2..22276a5 100644
--- a/swh/search/tests/conftest.py
+++ b/swh/search/tests/conftest.py
@@ -1,139 +1,142 @@
-# Copyright (C) 2019-2020  The Software Heritage developers
+# Copyright (C) 2019-2021  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import logging
 import socket
 import subprocess
 import time
 
 import elasticsearch
 import pytest
 
 from swh.search import get_search
 
 logger = logging.getLogger(__name__)
 
 
 def free_port():
     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     sock.bind(("127.0.0.1", 0))
     port = sock.getsockname()[1]
     sock.close()
     return port
 
 
 def wait_for_peer(addr, port):
     while True:
         try:
             sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             sock.connect((addr, port))
         except ConnectionRefusedError:
             time.sleep(0.1)
         else:
             sock.close()
             break
 
 
 CONFIG_TEMPLATE = """
 node.name: node-1
 path.data: {data}
 path.logs: {logs}
 network.host: 127.0.0.1
 http.port: {http_port}
 transport.port: {transport_port}
 """
 
 
-def _run_elasticsearch(conf_dir, data_dir, logs_dir, http_port, transport_port):
+def _run_elasticsearch(
+    conf_dir, data_dir, logs_dir, http_port, transport_port, libffi_tmpdir
+):
     es_home = "/usr/share/elasticsearch"
 
     with open(conf_dir + "/elasticsearch.yml", "w") as fd:
         fd.write(
             CONFIG_TEMPLATE.format(
                 data=data_dir,
                 logs=logs_dir,
                 http_port=http_port,
                 transport_port=transport_port,
             )
         )
 
     with open(conf_dir + "/log4j2.properties", "w") as fd:
         pass
 
     cmd = [
         "/usr/share/elasticsearch/jdk/bin/java",
         "-Des.path.home={}".format(es_home),
         "-Des.path.conf={}".format(conf_dir),
         "-Des.bundled_jdk=true",
         "-Dlog4j2.disable.jmx=true",
         "-cp",
         "{}/lib/*".format(es_home),
         "org.elasticsearch.bootstrap.Elasticsearch",
     ]
 
     host = "127.0.0.1:{}".format(http_port)
 
     with open(logs_dir + "/output.txt", "w") as fd:
-        p = subprocess.Popen(cmd)
+        p = subprocess.Popen(cmd, env={"LIBFFI_TMPDIR": libffi_tmpdir})
 
     wait_for_peer("127.0.0.1", http_port)
 
     client = elasticsearch.Elasticsearch([host])
     assert client.ping()
 
     return p
 
 
 @pytest.fixture(scope="session")
 def elasticsearch_session(tmpdir_factory):
     tmpdir = tmpdir_factory.mktemp("elasticsearch")
     es_conf = tmpdir.mkdir("conf")
 
     http_port = free_port()
     transport_port = free_port()
 
     p = _run_elasticsearch(
         conf_dir=str(es_conf),
         data_dir=str(tmpdir.mkdir("data")),
         logs_dir=str(tmpdir.mkdir("logs")),
         http_port=http_port,
         transport_port=transport_port,
+        libffi_tmpdir=str(tmpdir.mkdir("libffi")),
     )
 
     yield "127.0.0.1:{}".format(http_port)
 
     # Check ES didn't stop
     assert p.returncode is None, p.returncode
 
     p.kill()
     p.wait()
 
 
 @pytest.fixture(scope="class")
 def elasticsearch_host(elasticsearch_session):
     yield elasticsearch_session
 
 
 @pytest.fixture
 def swh_search(elasticsearch_host):
     """Instantiate a search client, initialize the elasticsearch instance,
     and returns it
 
     """
     logger.debug("swh_search: elasticsearch_host: %s", elasticsearch_host)
     search = get_search(
         "elasticsearch",
         hosts=[elasticsearch_host],
         indexes={
             "origin": {
                 "index": "test",
                 "read_alias": "test-read",
                 "write_alias": "test-write",
             }
         },
     )
     search.deinitialize()  # To reset internal state from previous runs
     search.initialize()  # install required index
     yield search