diff --git a/streetup/interventions/static/interventions/detail/cms_edit_mode.js b/streetup/interventions/static/interventions/detail/cms_edit_mode.js
index b4f2c18..4ae46be 100644
--- a/streetup/interventions/static/interventions/detail/cms_edit_mode.js
+++ b/streetup/interventions/static/interventions/detail/cms_edit_mode.js
@@ -509,6 +509,7 @@
 
     // Intercept form submissions to auto-save before submitting
     document.addEventListener('submit', async function(e) {
+        if (e.defaultPrevented) return;
         if (!isEditMode || isSubmittingAutoSavedForm || isAutoSavingAndNavigating) return;
 
         const form = e.target;
@@ -531,7 +532,7 @@
             console.error('Auto-save form submit error:', err);
             isAutoSavingAndNavigating = false;
         }
-    }, true);
+    });
 
     // Background auto-save on tab close / browser reload without showing alert
     function sendKeepAliveSave() {