diff --git a/services/web/frontend/js/features/source-editor/extensions/track-changes.ts b/services/web/frontend/js/features/source-editor/extensions/track-changes.ts
index c6188e1ea1..cee664ecc0 100644
--- a/services/web/frontend/js/features/source-editor/extensions/track-changes.ts
+++ b/services/web/frontend/js/features/source-editor/extensions/track-changes.ts
@@ -346,9 +346,15 @@ const trackChangesTheme = EditorView.baseTheme({
     position: 'absolute',
     left: 0,
     bottom: 0,
-    width: '10000px',
+    width: '100vw',
     borderBottom: '1px dashed black',
   },
+  // disable callout line in Firefox
+  '@supports (-moz-appearance:none)': {
+    '.ol-cm-change-callout-inner': {
+      display: 'none',
+    },
+  },
   '.ol-cm-change-callout-i .ol-cm-change-callout-inner': {
     borderColor: '#2c8e30',
   },