diff --git a/pubtools/exodus/_hooks/pulp.py b/pubtools/exodus/_hooks/pulp.py
index 70f6ad8..b48f6a4 100644
--- a/pubtools/exodus/_hooks/pulp.py
+++ b/pubtools/exodus/_hooks/pulp.py
@@ -24,8 +24,8 @@ def __init__(self):
     def pulp_repository_pre_publish(self, repository, options):
         """Invoked as the first step in publishing a Pulp repository.
 
-        This implementation adds to each config the --exodus-publish argument,
-        attaching the repository to an exodus-gw publish.
+        This implementation adds to each config the necessary arguments
+        to attach this repository's publish task to an exodus-gw publish.
 
         Args:
             repository (:class:`~pubtools.pulplib.Repository`):
@@ -48,6 +48,17 @@ def pulp_repository_pre_publish(self, repository, options):
             list(options.rsync_extra_args) if options.rsync_extra_args else []
         )
         args.append("--exodus-publish=%s" % self.publish["id"])
+
+        # 2023-10: by default, the pulp hook should always use phase1 commit.
+        # But since the functionality is relatively new, this is provided as an
+        # escape hatch in case it would need to be disabled in some environments
+        # for unanticipated reasons.
+        #
+        # Consider deleting this conditional once the functionality is proven
+        # in production.
+        if os.getenv("EXODUS_PULP_HOOK_PHASE1_COMMIT", "1") == "1":
+            args.append("--exodus-commit=phase1")
+
         return attr.evolve(options, rsync_extra_args=args)
 
     @property
diff --git a/tests/test_exodus_pulp_hooks.py b/tests/test_exodus_pulp_hooks.py
index 8ff759d..353b4d5 100644
--- a/tests/test_exodus_pulp_hooks.py
+++ b/tests/test_exodus_pulp_hooks.py
@@ -34,6 +34,7 @@ def test_exodus_pulp_typical(
             rsync_extra_args=[
                 "--existing-arg",
                 "--exodus-publish=497f6eca-6276-4993-bfeb-53cbbbba6f08",
+                "--exodus-commit=phase1",
             ],
         )
 
@@ -55,6 +56,27 @@ def test_exodus_pulp_typical(
         )
 
 
+def test_exodus_pulp_phase1_disabled(successful_gw_task, monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.setenv("EXODUS_PULP_HOOK_PHASE1_COMMIT", "0")
+
+    with task_context():
+        hook_rets = pm.hook.pulp_repository_pre_publish(
+            repository=None,
+            options=FakePublishOptions(rsync_extra_args=["--existing-arg"]),
+        )
+        hook_rets = [ret for ret in hook_rets if ret is not None]
+
+        # The pre-publish hook should've returned options with exodus-publish
+        # arg appended to existing rsync_extra_args, but this time it should
+        # NOT have added exodus-commit due to the above env var.
+        assert hook_rets[0] == FakePublishOptions(
+            rsync_extra_args=[
+                "--existing-arg",
+                "--exodus-publish=497f6eca-6276-4993-bfeb-53cbbbba6f08",
+            ],
+        )
+
+
 def test_exodus_pulp_no_publish(patch_env_vars, caplog):
     caplog.set_level(logging.DEBUG, "pubtools-exodus")