diff --git a/test/io-tests/configs/app-settings.config b/test/io-tests/configs/app-settings.config
index 3542ae82e..65408c91d 100644
--- a/test/io-tests/configs/app-settings.config
+++ b/test/io-tests/configs/app-settings.config
@@ -1,5 +1,2 @@
-db-pool = 1
-db-pool-timeout = 1
-
 app.settings.external_api_secret = "0123456789abcdef"
 db-config = false
diff --git a/test/io-tests/configs/base64-secret-from-file.config b/test/io-tests/configs/base64-secret-from-file.config
index 2a5eab44f..d31f6f5d8 100644
--- a/test/io-tests/configs/base64-secret-from-file.config
+++ b/test/io-tests/configs/base64-secret-from-file.config
@@ -1,5 +1,3 @@
-db-pool = 1
-
 # Read secret from a file: /dev/stdin (alias for standard input)
 jwt-secret = "@/dev/stdin"
 jwt-secret-is-base64 = true
diff --git a/test/io-tests/configs/dburi-from-file.config b/test/io-tests/configs/dburi-from-file.config
index 33586354e..a9d8441b0 100644
--- a/test/io-tests/configs/dburi-from-file.config
+++ b/test/io-tests/configs/dburi-from-file.config
@@ -1,4 +1,3 @@
 db-uri = "@/dev/stdin"
-db-pool = 1
 jwt-secret = "reallyreallyreallyreallyverysafe"
 db-config = false
diff --git a/test/io-tests/configs/role-claim-key.config b/test/io-tests/configs/role-claim-key.config
index d51d5fb64..dc22cf7ae 100644
--- a/test/io-tests/configs/role-claim-key.config
+++ b/test/io-tests/configs/role-claim-key.config
@@ -1,4 +1,3 @@
-db-pool = 1
 jwt-role-claim-key = "$(ROLE_CLAIM_KEY)"
 jwt-secret = "reallyreallyreallyreallyverysafe"
 db-config = false
diff --git a/test/io-tests/configs/secret-from-file.config b/test/io-tests/configs/secret-from-file.config
index df373590e..6be2deee4 100644
--- a/test/io-tests/configs/secret-from-file.config
+++ b/test/io-tests/configs/secret-from-file.config
@@ -1,5 +1,3 @@
-db-pool = 1
-
 # Read secret from a file: /dev/stdin (alias for standard input)
 jwt-secret = "@/dev/stdin"
 jwt-secret-is-base64 = false
diff --git a/test/io-tests/configs/sigusr2-settings-external-secret.config b/test/io-tests/configs/sigusr2-settings-external-secret.config
index 2dfda4a63..b3fe854e3 100644
--- a/test/io-tests/configs/sigusr2-settings-external-secret.config
+++ b/test/io-tests/configs/sigusr2-settings-external-secret.config
@@ -1,5 +1,3 @@
-db-pool = 1
-
 jwt-secret = "$(JWT_SECRET_FILE)"
 jwt-secret-is-base64 = false
 db-config = false
diff --git a/test/io-tests/configs/sigusr2-settings.config b/test/io-tests/configs/sigusr2-settings.config
index c8a1cb403..cc14ac709 100644
--- a/test/io-tests/configs/sigusr2-settings.config
+++ b/test/io-tests/configs/sigusr2-settings.config
@@ -1,5 +1,4 @@
 db-schemas = "public"
-db-pool = 1
 
 app.settings.name_var = "John"
 jwt-secret = "invalidinvalidinvalidinvalidinvalid"
diff --git a/test/io-tests/configs/simple.config b/test/io-tests/configs/simple.config
index 97512d3ec..b5833825e 100644
--- a/test/io-tests/configs/simple.config
+++ b/test/io-tests/configs/simple.config
@@ -1,3 +1,2 @@
-db-pool = 1
 jwt-secret = "reallyreallyreallyreallyverysafe"
 db-config = false
diff --git a/test/io-tests/test_io.py b/test/io-tests/test_io.py
index cc94ad2c1..734697b8f 100644
--- a/test/io-tests/test_io.py
+++ b/test/io-tests/test_io.py
@@ -138,6 +138,8 @@ def dumpconfig(configpath=None, env=None, stdin=None):
 def run(configpath=None, stdin=None, env=None, port=None):
     "Run PostgREST and yield an endpoint that is ready for connections."
     env = env or {}
+    env["PGRST_DB_POOL"] = "1"
+    env["PGRST_DB_POOL_TIMEOUT"] = "1"
 
     with tempfile.TemporaryDirectory() as tmpdir:
         if port:
@@ -454,7 +456,7 @@ def test_iat_claim(defaultenv):
             response = postgrest.session.get("/authors_only", headers=headers)
             assert response.status_code == 200
 
-            time.sleep(0.5)
+            time.sleep(0.1)
 
 
 def test_app_settings(defaultenv):
@@ -610,7 +612,7 @@ def test_db_schema_notify_reload(defaultenv):
             "/rpc/change_db_schema_and_full_reload", data={"schemas": "v1"}
         )
 
-        time.sleep(0.5)
+        time.sleep(0.1)
 
         response = postgrest.session.get("/rpc/get_guc_value?name=search_path")
         assert response.text == '"v1, public"'