diff --git a/src/tox_current_env/hooks4.py b/src/tox_current_env/hooks4.py
index 40a263b..5628eff 100644
--- a/src/tox_current_env/hooks4.py
+++ b/src/tox_current_env/hooks4.py
@@ -15,6 +15,11 @@ from tox.plugin import impl
 from tox.tox_env.python.api import PythonInfo
 from tox.tox_env.python.runner import PythonRun
 
+try:
+    import importlib.metadata as importlib_metadata
+except ImportError:
+    import importlib_metadata
+
 
 @impl
 def tox_register_tox_env(register):
@@ -106,6 +111,15 @@ class Installer:
     def install(self, *args, **kwargs):
         return None
 
+    def installed(self):
+        """Return list of installed packages like `pip freeze`."""
+        return [
+            "{}=={}".format(d.metadata.get("name"), d.version)
+            for d in sorted(
+                importlib_metadata.distributions(), key=lambda d: d.metadata.get("name")
+            )
+        ]
+
 
 class CurrentEnvLocalSubProcessExecutor(Execute):
     def build_instance(
diff --git a/tests/test_integration_tox4.py b/tests/test_integration_tox4.py
index 90cf7df..34e8b0d 100644
--- a/tests/test_integration_tox4.py
+++ b/tests/test_integration_tox4.py
@@ -421,3 +421,12 @@ def test_pass_env(projdir, pass_env):
     assert result.returncode == 0
     assert "\nassertme\n" in result.stdout
     assert "\nNone\n" not in result.stdout
+
+
+def test_report_installed(projdir):
+    # tox4 only reports installed when a CI is detected
+    env = {"CI": "true"}
+    result = tox("-e", NATIVE_TOXENV, "--current-env", env=env, quiet=False)
+    assert result.returncode == 0
+    assert "tox==" in result.stdout
+    assert "pytest==" in result.stdout