diff --git a/lanshare/static/index.html b/lanshare/static/index.html
index 3221900..9eb60e3 100644
--- a/lanshare/static/index.html
+++ b/lanshare/static/index.html
@@ -1004,8 +1004,9 @@
         // Update peer count
         peerCount.textContent = state.peers.size;
         
-        // Update sharing buttons
-        startShareBtn.classList.toggle('hidden', state.isSharing);
+        // Update sharing buttons (hide entirely if browser lacks getDisplayMedia)
+        const canShare = !!navigator.mediaDevices?.getDisplayMedia;
+        startShareBtn.classList.toggle('hidden', state.isSharing || !canShare);
         stopShareBtn.classList.toggle('hidden', !state.isSharing);
         
         // Update screen list