diff --git a/main.py b/main.py
index 3b3509c..84b2d50 100755
--- a/main.py
+++ b/main.py
@@ -31,10 +31,6 @@
     "Read": do_system_read,
 })
 
-base_env = {
-    "System": system_module,
-}
-
 def resolve_value(env, value):
     (type, value) = value
     if type == "reference":
@@ -89,8 +85,11 @@
     ast = parse.parse_file()
     if not ast:
         return 1
+    env = {
+        "System": system_module,
+    }
     for command in ast:
-        run_command(base_env, command)
+        run_command(env, command)
     return 0
 
 if __name__ == "__main__":