diff --git a/eval.py b/eval.py
index 9d42089fbcab5893b98bb8a80d99ca7ac901cfd7..f906ed8799cee69d7ac5743a02a6af9f93c5c6e1 100755
--- a/eval.py
+++ b/eval.py
@@ -19,7 +19,12 @@ SERVER_DIR = ROOT_DIR / 'servers'
 ARTIFACT_DESC = subprocess.check_output(
     'git describe --dirty --always'.split(), cwd=ROOT_DIR, text=True)[:-1]
 
-EMPER_20_WORKER_ENV_CMD = 'env EMPER_WORKER_COUNT=20'
+
+def emper_create_env_worker_count(worker_count):
+    return f'EMPER_WORKER_COUNT={worker_count}'
+
+
+EMPER_20_WORKER_ENV_CMD = f'env emper_create_env_worker_count(20)'
 GO_20_WORKER_ENV_CMD = 'env GOMAXPROCS=20'
 TOKIO_20_WORKER_ENV_CMD = 'env TOKIO_WORKER_COUNT=20'
 
@@ -170,7 +175,7 @@ EMPER_FLAVORS = {
         'checkout': EMPER_FIRST_CHECKOUT
     },
     '4': {
-        'patches': ['4.patch']
+        'server_cmd_prefix': f'env emper_create_env_worker_count(4)'
     },
     '20': {
         'server_cmd_prefix': EMPER_20_WORKER_ENV_CMD