diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 4bcf159..06285e9 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -1169,7 +1169,7 @@
                         # potential deadlocks, thus we do all this here.
                         # and pass it to fork_exec()
 
-                        if env:
+                        if env is not None:
                             env_list = [os.fsencode(k) + b'=' + os.fsencode(v)
                                         for k, v in env.items()]
                         else: