diff --git a/src/formatitko/command_util.py b/src/formatitko/command_util.py
index 002aa8c..f11a154 100644
--- a/src/formatitko/command_util.py
+++ b/src/formatitko/command_util.py
@@ -16,9 +16,9 @@ def parse_command(code: str) -> CommandCallable:
 	for line in code_lines:
 		indented_code_lines.append(("\t" if tabs else "    ")+line)
 	code = "def command(element: Command, context: Context) -> list[Element]:\n"+"\n".join(indented_code_lines)
-	command_env = command_env.__dict__
-	exec(code, command_env)
-	return command_env["command"]
+	env = {**command_env.__dict__}
+	exec(code, env)
+	return env["command"]
 
 # This function is called in trasform.py, defining a command which can be
 # called later