diff --git a/README.rst b/README.rst
index 74d20d6..caa565b 100644
--- a/README.rst
+++ b/README.rst
@@ -347,27 +347,26 @@ For specifics, see `pip_run.run()
 Environment Persistence
 =======================
 
-``pip-run`` honors the ``PIP_RUN_MODE`` variable. If unset or
-set to ``ephemeral``, dependencies are installed to an ephemeral
-temporary directory on each invocation (and deleted after).
-Setting this variable to ``persist`` will instead create or re-use
-a directory in the user's cache, only installing the dependencies if
-the directory doesn't already exist. A separate cache is maintained
-for each combination of requirements specified.
-
-``persist`` mode can greatly improve startup performance at the
-expense of staleness and accumulated cruft.
-
-Without ``PIP_RUN_MODE=persist`` (or with ``=ephemeral``), ``pip-run`` will
-re-install dependencies every time a script runs, silently adding to the
-startup time while dependencies are installed into an ephemeral environment,
-depending on how many dependencies there are and whether the dependencies have
-been previously downloaded to the local pip cache. Use ``pip-run -v ...`` to
-see the installation activity.
+``pip-run`` honors the ``PIP_RUN_RETENTION_STRATEGY`` variable. If unset or
+set to ``destroy``, dependencies are installed to a temporary directory on
+each invocation (and deleted after). Setting this variable to ``persist`` will
+instead create or re-use a directory in the user's cache, only installing the
+dependencies if the directory doesn't already exist. A separate cache is
+maintained for each combination of requirements specified.
+
+``persist`` strategy can greatly improve startup performance at the expense of
+staleness and accumulated cruft.
+
+Without ``PIP_RUN_RETENTION_STRATEGY=persist`` (or with ``=destroy``),
+``pip-run`` will re-install dependencies every time a script runs, silently
+adding to the startup time while dependencies are installed into an ephemeral
+environment, depending on how many dependencies there are and whether the
+dependencies have been previously downloaded to the local pip cache. Use
+``pip-run -v ...`` to see the installation activity.
 
 The location of the cache can be revealed with this command::
 
-    py -c 'import importlib; print(importlib.import_module("pip_run.mode.persist").paths.user_cache_path)'
+    py -c 'import importlib; print(importlib.import_module("pip_run.retention.persist").paths.user_cache_path)'
 
 
 Limitations
diff --git a/conftest.py b/conftest.py
index ac9fcdc..817bcc8 100644
--- a/conftest.py
+++ b/conftest.py
@@ -51,7 +51,7 @@ class Paths:
     monkeypatch_session.setattr(pip_run.retention.persist, 'paths', Paths)
 
 
-@pytest.fixture(params=['persist', 'ephemeral'])
+@pytest.fixture(params=['persist', 'destroy'])
 def retention_strategy(monkeypatch, request):
     monkeypatch.setenv('PIP_RUN_RETENTION_STRATEGY', request.param)
 
diff --git a/pip_run/deps.py b/pip_run/deps.py
index 992d330..cb59310 100644
--- a/pip_run/deps.py
+++ b/pip_run/deps.py
@@ -60,12 +60,12 @@ def _mode_compat():
             'PIP_RUN_MODE is deprecated. Use PIP_RUN_RETENTION_STRATEGY instead.',
             DeprecationWarning,
         )
-        return mode
+        return mode.replace('ephemeral', 'destroy')
 
 
 def retention_strategy():
     strategy = (
-        os.environ.get('PIP_RUN_RETENTION_STRATEGY') or _mode_compat() or 'ephemeral'
+        os.environ.get('PIP_RUN_RETENTION_STRATEGY') or _mode_compat() or 'destroy'
     )
     return importlib.import_module(f'.retention.{strategy}', package=__package__)
 
diff --git a/pip_run/retention/ephemeral.py b/pip_run/retention/destroy.py
similarity index 100%
rename from pip_run/retention/ephemeral.py
rename to pip_run/retention/destroy.py