diff --git a/CHANGELOG.md b/CHANGELOG.md
index ceb6ff539..b2d4023e3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -120,6 +120,7 @@
   - reference: fix download for sd15/sdxl reference models  
   - fix checks in init/mask image decode  
   - fix hf token with extra chars  
+  - image viewer refocus on gallery after returning from full screen mode  
 
 ## Update for 2025-09-15
 
diff --git a/extensions-builtin/sdnext-modernui b/extensions-builtin/sdnext-modernui
index 85ab79ed0..39277a468 160000
--- a/extensions-builtin/sdnext-modernui
+++ b/extensions-builtin/sdnext-modernui
@@ -1 +1 @@
-Subproject commit 85ab79ed0f8a9c8484e2b2372d745527ebc84e7d
+Subproject commit 39277a4688473e1e5fdb8a6173c8ded28c0439e1
diff --git a/javascript/imageViewer.js b/javascript/imageViewer.js
index 5631c173b..e7eaca7a8 100644
--- a/javascript/imageViewer.js
+++ b/javascript/imageViewer.js
@@ -15,11 +15,20 @@ function cycleImageFit() {
   log('cycleImageFit', current, next);
 }
 
+function isInViewport(element) {
+  const rect = element.getBoundingClientRect();
+  return rect.top >= 0 && rect.left >= 0 && rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) && rect.right <= (window.innerWidth || document.documentElement.clientWidth);
+}
+
 function closeModal(evt, force = false) {
   if (force) gradioApp().getElementById('lightboxModal').style.display = 'none';
   if (previewDrag) return;
   if (evt?.button !== 0) return;
   gradioApp().getElementById('lightboxModal').style.display = 'none';
+  let thumbnails = Array.from(gradioApp().querySelectorAll('.thumbnails .thumbnail-item'));
+  thumbnails = thumbnails.filter((el) => el.checkVisibility());
+  if (thumbnails.length === 0) return;
+  thumbnails[0].focus();
 }
 
 function modalImageSwitch(offset) {