diff --git a/src/main/java/name/nathanmcrae/numbersstation/MainSettingsController.java b/src/main/java/name/nathanmcrae/numbersstation/MainSettingsController.java
index d33a42b..2b02eba 100644
--- a/src/main/java/name/nathanmcrae/numbersstation/MainSettingsController.java
+++ b/src/main/java/name/nathanmcrae/numbersstation/MainSettingsController.java
@@ -311,6 +311,8 @@ public class MainSettingsController {
                 };
             }
         });
+
+        externalProgramCommandField.disableProperty().bind(externalProgramRadioButton.selectedProperty().not());
     }
 
     @FXML