diff --git a/kitty/boss.py b/kitty/boss.py
index 56e1fa956..028bd8b04 100755
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -1221,6 +1221,8 @@ class Boss:
         cwd_from: Optional[int] = None
     ) -> None:
         import subprocess
+        if env:
+            env = {**os.environ, **env}
         if cwd_from:
             with suppress(Exception):
                 cwd = cwd_of_process(cwd_from)