diff --git a/oephys2nix/main.py b/oephys2nix/main.py
index 1c783f1..34b1f5c 100644
--- a/oephys2nix/main.py
+++ b/oephys2nix/main.py
@@ -27,7 +27,7 @@ def main(
         readable=True,
         resolve_path=True,
     ),
-    ttl: bool = typer.Option(default=True, help="For recordings that did not have a ttl pulse"),
+    no_ttl: bool = typer.Option(False, help="For recordings that did not have a ttl pulse"),
     overwrite: bool = typer.Option(default=True, help="Overwrites nix file"),
     debug: bool = typer.Option(default=True, help="Shows more information and plots the results"),
 ) -> None: