diff --git a/test/int/conftest.py b/test/int/conftest.py
index 57926ac9dea8497a3115c9e92ab9fd2b4cdf36ec..fef898623b3392514b9f18cf7650cd360ccf6365 100644
--- a/test/int/conftest.py
+++ b/test/int/conftest.py
@@ -234,7 +234,7 @@ class Instance:
 
         self.process = subprocess.Popen(
             self.command,
-            env=self.env or {},
+            env=self.env or None,
             stdin=subprocess.DEVNULL,
             start_new_session=True,
         )