diff --git a/shell/main.cpp b/shell/main.cpp
index 70c68a2b..026475af 100644
--- a/shell/main.cpp
+++ b/shell/main.cpp
@@ -85,6 +85,7 @@ Result<int> luna_main(int argc, char** argv)
 {
     StringView path;
     StringView command;
+    bool interactive { false };
 
     SharedPtr<File> input_file;
 
@@ -93,6 +94,7 @@ Result<int> luna_main(int argc, char** argv)
     parser.add_system_program_info("sh"_sv);
     parser.add_positional_argument(path, "path"_sv, "-"_sv);
     parser.add_value_argument(command, 'c', "command"_sv, "execute a single command and then exit"_sv);
+    parser.add_switch_argument(interactive, 'i', "interactive"_sv, "run an interactive shell"_sv);
     parser.parse(argc, argv);
 
     // TODO: This does not properly handle builtins.
@@ -105,7 +107,7 @@ Result<int> luna_main(int argc, char** argv)
         input_file->set_close_on_exec();
     }
 
-    bool interactive = isatty(input_file->fd());
+    if (isatty(input_file->fd())) interactive = true;
 
     if (interactive)
     {