diff --git a/Changelog.md b/Changelog.md
index 877616b8..366f3570 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -3,7 +3,7 @@ All notable changes to this project will be documented here.
 
 ## [unreleased]
 - Add tidyverse as a default R tester package (#512)
-- For the Haskell tester, make stack resolver a test and environment setting (#526)
+- For the Haskell tester, make stack resolver a test setting (#526)
 
 ## [v2.4.3]
 - Omit skipped test cases in Python tester (#522)
diff --git a/docker-compose.yml b/docker-compose.yml
index 351e49a6..90b52b1c 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -19,7 +19,6 @@ services:
       - SUPERVISOR_URL=127.0.0.1:9001
       - AUTOTESTER_CONFIG=/app/.dockerfiles/docker-config.yml
       - STACK_ROOT=/home/docker/.autotesting/.stack
-      - STACK_RESOLVER=lts-16.17
     depends_on:
       - postgres
       - redis
diff --git a/server/autotest_server/__init__.py b/server/autotest_server/__init__.py
index 4d26d1b4..217421e3 100644
--- a/server/autotest_server/__init__.py
+++ b/server/autotest_server/__init__.py
@@ -396,8 +396,6 @@ def update_test_settings(user, settings_id, test_settings, file_url):
             default_env = os.path.join(TEST_SCRIPT_DIR, DEFAULT_ENV_DIR)
             if not os.path.isdir(default_env):
                 subprocess.run([sys.executable, "-m", "venv", default_env], check=True)
-                requirements_path = os.path.join(os.path.dirname(__file__), "../requirements.txt")
-                subprocess.run([f"{default_env}/bin/pip", "install", "-r", requirements_path], check=True)
             try:
                 tester_settings["_env"] = tester_install.create_environment(tester_settings, env_dir, default_env)
             except Exception as e:
diff --git a/server/autotest_server/settings.yml b/server/autotest_server/settings.yml
index 4d32c71f..0325289b 100644
--- a/server/autotest_server/settings.yml
+++ b/server/autotest_server/settings.yml
@@ -1,7 +1,6 @@
 workspace: !ENV ${WORKSPACE}
 redis_url: !ENV ${REDIS_URL}
 supervisor_url: !ENV ${SUPERVISOR_URL}
-stack_resolver: !ENV ${STACK_RESOLVER}
 workers:
   - user: !ENV ${USER}
     queues:
diff --git a/server/autotest_server/testers/haskell/settings_schema.json b/server/autotest_server/testers/haskell/settings_schema.json
index b0b288f2..5fd49f3d 100644
--- a/server/autotest_server/testers/haskell/settings_schema.json
+++ b/server/autotest_server/testers/haskell/settings_schema.json
@@ -20,7 +20,7 @@
         "resolver_version": {
           "title": "Resolver version",
           "type": "string",
-          "enum": []
+          "default": null
         }
       }
     },
diff --git a/server/autotest_server/testers/haskell/setup.py b/server/autotest_server/testers/haskell/setup.py
index 0cafd871..f1b3efa0 100644
--- a/server/autotest_server/testers/haskell/setup.py
+++ b/server/autotest_server/testers/haskell/setup.py
@@ -1,14 +1,14 @@
 import os
 import json
 import subprocess
-from ...config import config
 
 HASKELL_TEST_DEPS = ["tasty-discover", "tasty-quickcheck"]
+STACK_RESOLVER = "lts-16.17"
 
 
 def create_environment(_settings, _env_dir, default_env_dir):
     env_data = _settings.get("env_data", {})
-    resolver = env_data.get("resolver_version", config["stack_resolver"])
+    resolver = env_data.get("resolver_version", STACK_RESOLVER)
     cmd = ["stack", "build", "--resolver", resolver, "--system-ghc", *HASKELL_TEST_DEPS]
     subprocess.run(cmd, check=True)
 
@@ -17,7 +17,7 @@ def create_environment(_settings, _env_dir, default_env_dir):
 
 def install():
     subprocess.run(os.path.join(os.path.dirname(os.path.realpath(__file__)), "requirements.system"), check=True)
-    resolver = config["stack_resolver"]
+    resolver = STACK_RESOLVER
     cmd = ["stack", "build", "--resolver", resolver, "--system-ghc", *HASKELL_TEST_DEPS]
     subprocess.run(cmd, check=True)
     subprocess.run(
@@ -28,8 +28,6 @@ def install():
 def settings():
     with open(os.path.join(os.path.dirname(os.path.realpath(__file__)), "settings_schema.json")) as f:
         settings_ = json.load(f)
-    resolvers = [config["stack_resolver"]]
     resolver_versions = settings_["properties"]["env_data"]["properties"]["resolver_version"]
-    resolver_versions["enum"] = resolvers
-    resolver_versions["default"] = resolvers[-1]
+    resolver_versions["default"] = STACK_RESOLVER
     return settings_