diff --git a/test_runner/regress/test_pg_regress.py b/test_runner/regress/test_pg_regress.py
index 756a2c17c9..3636260038 100644
--- a/test_runner/regress/test_pg_regress.py
+++ b/test_runner/regress/test_pg_regress.py
@@ -21,6 +21,15 @@ if TYPE_CHECKING:
     from pytest import CaptureFixture
 
 
+TENANT_CONF = {
+    # Scaled down thresholds so that we are exercising the pageserver beyond just writing
+    # ephemeral/L0 layers, and because debug-mode code is slow to read from full sized ephemeral layer files.
+    "pitr_interval": "60s",
+    "checkpoint_distance": f"{8 * 1024 * 1024}",
+    "compaction_target_size": f"{8 * 1024 * 1024}",
+}
+
+
 # Run the main PostgreSQL regression tests, in src/test/regress.
 #
 @pytest.mark.timeout(600)
@@ -45,7 +54,10 @@ def test_pg_regress(
 
     neon_env_builder.enable_pageserver_remote_storage(s3_storage())
     neon_env_builder.enable_scrub_on_exit()
-    env = neon_env_builder.init_start(initial_tenant_shard_count=shard_count)
+    env = neon_env_builder.init_start(
+        initial_tenant_conf=TENANT_CONF,
+        initial_tenant_shard_count=shard_count,
+    )
 
     # Connect to postgres and create a database called "regression".
     endpoint = env.endpoints.create_start("main")
@@ -163,7 +175,9 @@ def test_isolation(
         neon_env_builder.num_pageservers = shard_count
     neon_env_builder.enable_pageserver_remote_storage(s3_storage())
     neon_env_builder.enable_scrub_on_exit()
-    env = neon_env_builder.init_start(initial_tenant_shard_count=shard_count)
+    env = neon_env_builder.init_start(
+        initial_tenant_conf=TENANT_CONF, initial_tenant_shard_count=shard_count
+    )
 
     # Connect to postgres and create a database called "regression".
     # isolation tests use prepared transactions, so enable them
@@ -219,7 +233,9 @@ def test_sql_regress(
         neon_env_builder.num_pageservers = shard_count
     neon_env_builder.enable_pageserver_remote_storage(s3_storage())
     neon_env_builder.enable_scrub_on_exit()
-    env = neon_env_builder.init_start(initial_tenant_shard_count=shard_count)
+    env = neon_env_builder.init_start(
+        initial_tenant_conf=TENANT_CONF, initial_tenant_shard_count=shard_count
+    )
 
     # Connect to postgres and create a database called "regression".
     endpoint = env.endpoints.create_start("main")