diff --git a/test_runner/regress/test_pageserver_generations.py b/test_runner/regress/test_pageserver_generations.py
index 7020a61b2f..67f68a62af 100644
--- a/test_runner/regress/test_pageserver_generations.py
+++ b/test_runner/regress/test_pageserver_generations.py
@@ -22,6 +22,7 @@ from fixtures.neon_fixtures import (
     NeonPageserver,
     PgBin,
     S3Scrubber,
+    flush_ep_to_pageserver,
     last_flush_lsn_upload,
 )
 from fixtures.pageserver.http import PageserverApiException
@@ -30,6 +31,7 @@ from fixtures.pageserver.utils import (
     list_prefix,
     wait_for_last_record_lsn,
     wait_for_upload,
+    wait_for_upload_queue_empty,
 )
 from fixtures.remote_storage import (
     RemoteStorageKind,
@@ -120,6 +122,17 @@ def generate_uploads_and_deletions(
         print_gc_result(gc_result)
         assert gc_result["layers_removed"] > 0
 
+        # Stop endpoint and flush all data to pageserver, then checkpoint it: this
+        # ensures that the pageserver is in a fully idle state: there will be no more
+        # background ingest, no more uploads pending, and therefore no non-determinism
+        # in subsequent actions like pageserver restarts.
+        final_lsn = flush_ep_to_pageserver(env, endpoint, tenant_id, timeline_id, pageserver.id)
+        ps_http.timeline_checkpoint(tenant_id, timeline_id)
+        # Finish uploads
+        wait_for_upload(ps_http, tenant_id, timeline_id, final_lsn)
+        # Finish all remote writes (including deletions)
+        wait_for_upload_queue_empty(ps_http, tenant_id, timeline_id)
+
 
 def read_all(
     env: NeonEnv, tenant_id: Optional[TenantId] = None, timeline_id: Optional[TimelineId] = None
diff --git a/test_runner/regress/test_storage_controller.py b/test_runner/regress/test_storage_controller.py
index 405aa22831..840f354142 100644
--- a/test_runner/regress/test_storage_controller.py
+++ b/test_runner/regress/test_storage_controller.py
@@ -1187,7 +1187,14 @@ def test_storcon_cli(neon_env_builder: NeonEnvBuilder):
     storcon_cli(["node-configure", "--node-id", "1", "--scheduling", "pause"])
     assert "Pause" in storcon_cli(["nodes"])[3]
 
-    # Make a node offline
+    # We will simulate a node death and then marking it offline
+    env.pageservers[0].stop(immediate=True)
+    # Sleep to make it unlikely that the controller's heartbeater will race handling
+    # a /utilization response internally, such that it marks the node back online.  IRL
+    # there would always be a longer delay than this before a node failing and a human
+    # intervening.
+    time.sleep(2)
+
     storcon_cli(["node-configure", "--node-id", "1", "--availability", "offline"])
     assert "Offline" in storcon_cli(["nodes"])[3]