diff --git a/frontend/src/app.js b/frontend/src/app.js
index 35f4a4da5..6236fbd3e 100644
--- a/frontend/src/app.js
+++ b/frontend/src/app.js
@@ -109,7 +109,7 @@ const router = new Router({
 });
 
 router.beforeEach((to, from, next) => {
-  if (document.documentElement.className) {
+  if (document.querySelector(".v-dialog--active.v-dialog--fullscreen")) {
     // Disable back button in full-screen viewers and editors.
     next(false);
   } else if (to.matched.some((record) => record.meta.settings) && config.values.disable.settings) {
diff --git a/frontend/src/share.js b/frontend/src/share.js
index 3f8ffc907..adcea4ba2 100644
--- a/frontend/src/share.js
+++ b/frontend/src/share.js
@@ -109,7 +109,7 @@ const router = new Router({
 });
 
 router.beforeEach((to, from, next) => {
-  if (document.documentElement.className) {
+  if (document.querySelector(".v-dialog--active.v-dialog--fullscreen")) {
     // Disable back button in full-screen viewers and editors.
     next(false);
   } else if (to.matched.some((record) => record.meta.settings) && config.values.disable.settings) {