diff --git a/tox.ini b/tox.ini
index bc78f2496..c76b8a620 100644
--- a/tox.ini
+++ b/tox.ini
@@ -84,6 +84,11 @@ setenv =
   OS_VOLUME_API_VERSION = 3
   # must define this here so it can be inherited by the -py3* environments
   OS_CINDERCLIENT_EXEC_DIR = {envdir}/bin
+  # Our functional tests contain their own timeout handling, so
+  # turn off the timeout handling provided by the
+  # tempest.lib.base.BaseTestCase that our ClientTestBase class
+  # inherits from.
+  OS_TEST_TIMEOUT=0
 
 # The OS_CACERT environment variable should be passed to the test
 # environments to specify a CA bundle file to use in verifying a