diff --git a/.cirrus.yml b/.cirrus.yml
index 1b34aeb291..5f8d969c6f 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -9,6 +9,7 @@ task:
     MAKEJOBS: "-j9"
     CONFIGURE_OPTS: "--disable-dependency-tracking"
     GOAL: "install"
+    TEST_RUNNER_PORT_MIN: "14000"  # Must be larger than 12321, which is used for the http cache. See https://cirrus-ci.org/guide/writing-tasks/#http-cache
     CCACHE_SIZE: "200M"
     CCACHE_COMPRESS: 1
     CCACHE_DIR: "/tmp/ccache_dir"
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index cabb2182cb..d781d54811 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -9,6 +9,7 @@ from base64 import b64encode
 from binascii import unhexlify
 from decimal import Decimal, ROUND_DOWN
 import hashlib
+from subprocess import CalledProcessError
 import inspect
 import json
 import logging
@@ -16,7 +17,6 @@ import os
 import random
 import shutil
 import re
-from subprocess import CalledProcessError
 import time
 
 from . import coverage
@@ -261,10 +261,11 @@ def wait_until(predicate, *, attempts=float('inf'), timeout=float('inf'), sleep=
 # The maximum number of nodes a single test can spawn
 MAX_NODES = 15
 # Don't assign rpc or p2p ports lower than this
-PORT_MIN = 11000
+PORT_MIN = int(os.getenv('TEST_RUNNER_PORT_MIN', default=11000))
 # The number of ports to "reserve" for p2p and rpc, each
 PORT_RANGE = 5000
 
+
 class PortSeed:
     # Must be initialized with a unique integer for each process
     n = None