diff --git a/test_runner/regress/test_branch_and_gc.py b/test_runner/regress/test_branch_and_gc.py
index d7c4cf059a..43140c05ff 100644
--- a/test_runner/regress/test_branch_and_gc.py
+++ b/test_runner/regress/test_branch_and_gc.py
@@ -53,7 +53,7 @@ def test_branch_and_gc(neon_simple_env: NeonEnv, build_type: str):
     env = neon_simple_env
     pageserver_http_client = env.pageserver.http_client()
 
-    tenant, _ = env.neon_cli.create_tenant(
+    tenant, timeline_main = env.neon_cli.create_tenant(
         conf={
             # disable background GC
             "gc_period": "0s",
@@ -70,8 +70,7 @@ def test_branch_and_gc(neon_simple_env: NeonEnv, build_type: str):
         }
     )
 
-    timeline_main = env.neon_cli.create_timeline("test_main", tenant_id=tenant)
-    endpoint_main = env.endpoints.create_start("test_main", tenant_id=tenant)
+    endpoint_main = env.endpoints.create_start("main", tenant_id=tenant)
 
     main_cur = endpoint_main.connect().cursor()
 
@@ -92,7 +91,7 @@ def test_branch_and_gc(neon_simple_env: NeonEnv, build_type: str):
     pageserver_http_client.timeline_gc(tenant, timeline_main, lsn2 - lsn1 + 1024)
 
     env.neon_cli.create_branch(
-        "test_branch", "test_main", tenant_id=tenant, ancestor_start_lsn=lsn1
+        "test_branch", ancestor_branch_name="main", ancestor_start_lsn=lsn1, tenant_id=tenant
     )
     endpoint_branch = env.endpoints.create_start("test_branch", tenant_id=tenant)
 
diff --git a/test_runner/regress/test_pageserver_restart.py b/test_runner/regress/test_pageserver_restart.py
index bbf82fea4c..bd47a30428 100644
--- a/test_runner/regress/test_pageserver_restart.py
+++ b/test_runner/regress/test_pageserver_restart.py
@@ -174,8 +174,7 @@ def test_pageserver_chaos(
             "checkpoint_distance": "5000000",
         }
     )
-    env.neon_cli.create_timeline("test_pageserver_chaos", tenant_id=tenant)
-    endpoint = env.endpoints.create_start("test_pageserver_chaos", tenant_id=tenant)
+    endpoint = env.endpoints.create_start("main", tenant_id=tenant)
 
     # Create table, and insert some rows. Make it big enough that it doesn't fit in
     # shared_buffers, otherwise the SELECT after restart will just return answer
diff --git a/test_runner/regress/test_tenants_with_remote_storage.py b/test_runner/regress/test_tenants_with_remote_storage.py
index 168876b711..6ecc903192 100644
--- a/test_runner/regress/test_tenants_with_remote_storage.py
+++ b/test_runner/regress/test_tenants_with_remote_storage.py
@@ -71,10 +71,9 @@ def test_tenants_many(neon_env_builder: NeonEnvBuilder):
                 "checkpoint_distance": "5000000",
             }
         )
-        env.neon_cli.create_timeline("test_tenants_many", tenant_id=tenant)
 
         endpoint = env.endpoints.create_start(
-            "test_tenants_many",
+            "main",
             tenant_id=tenant,
         )
         tenants_endpoints.append((tenant, endpoint))
diff --git a/test_runner/regress/test_truncate.py b/test_runner/regress/test_truncate.py
index 52f125ce0b..bfa9ce5db7 100644
--- a/test_runner/regress/test_truncate.py
+++ b/test_runner/regress/test_truncate.py
@@ -26,8 +26,7 @@ def test_truncate(neon_env_builder: NeonEnvBuilder, zenbenchmark):
         }
     )
 
-    env.neon_cli.create_timeline("test_truncate", tenant_id=tenant)
-    endpoint = env.endpoints.create_start("test_truncate", tenant_id=tenant)
+    endpoint = env.endpoints.create_start("main", tenant_id=tenant)
     cur = endpoint.connect().cursor()
     cur.execute("create table t1(x integer)")
     cur.execute(f"insert into t1 values (generate_series(1,{n_records}))")