diff --git a/voice.py b/voice.py
index e571889..fdfaf93 100644
--- a/voice.py
+++ b/voice.py
@@ -189,14 +189,15 @@ class VoiceSession:
                         break
                     await asyncio.sleep(0.1)
 
-            # E2EE disabled — Element Call key derivation mismatch not yet resolved.
-            # Audio pipeline confirmed working without E2EE.
+            # Use caller's key as shared key for E2EE
             if self._e2ee_key:
-                logger.info("Caller E2EE key available (%d bytes) — E2EE disabled pending fix",
-                            len(self._e2ee_key))
+                logger.info("Enabling E2EE with caller's key (%d bytes)", len(self._e2ee_key))
                 if self._publish_key_cb:
                     self._publish_key_cb(self._e2ee_key)
-            e2ee_opts = None
+                e2ee_opts = _build_e2ee_options(self._e2ee_key)
+            else:
+                logger.warning("No E2EE key available, connecting without encryption")
+                e2ee_opts = None
 
             room_opts = rtc.RoomOptions(e2ee=e2ee_opts)
             self.lk_room = rtc.Room()