diff --git a/src/TextForEvent.js b/src/TextForEvent.js
index 6a2744109bd..cdfea45ad7c 100644
--- a/src/TextForEvent.js
+++ b/src/TextForEvent.js
@@ -444,10 +444,19 @@ function textForHistoryVisibilityEvent(event) {
 
 function textForEncryptionEvent(event) {
     const senderName = event.sender ? event.sender.name : event.getSender();
-    return _t('%(senderName)s turned on end-to-end encryption (algorithm %(algorithm)s).', {
-        senderName,
-        algorithm: event.getContent().algorithm,
-    });
+    if (event.getContent().algorithm === "m.megolm.v1.aes-sha2") {
+        return _t('%(senderName)s turned on end-to-end encryption.', {
+            senderName,
+        });
+    }
+    return _t(
+        '%(senderName)s turned on end-to-end encryption ' +
+        '(unrecognised algorithm %(algorithm)s).',
+        {
+            senderName,
+            algorithm: event.getContent().algorithm,
+        },
+    );
 }
 
 // Currently will only display a change if a user's power level is changed
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index c3ad3d19013..79f5731aed5 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -256,7 +256,8 @@
     "%(senderName)s made future room history visible to all room members.": "%(senderName)s made future room history visible to all room members.",
     "%(senderName)s made future room history visible to anyone.": "%(senderName)s made future room history visible to anyone.",
     "%(senderName)s made future room history visible to unknown (%(visibility)s).": "%(senderName)s made future room history visible to unknown (%(visibility)s).",
-    "%(senderName)s turned on end-to-end encryption (algorithm %(algorithm)s).": "%(senderName)s turned on end-to-end encryption (algorithm %(algorithm)s).",
+    "%(senderName)s turned on end-to-end encryption.": "%(senderName)s turned on end-to-end encryption.",
+    "%(senderName)s turned on end-to-end encryption (unrecognised algorithm %(algorithm)s).": "%(senderName)s turned on end-to-end encryption (unrecognised algorithm %(algorithm)s).",
     "%(userId)s from %(fromPowerLevel)s to %(toPowerLevel)s": "%(userId)s from %(fromPowerLevel)s to %(toPowerLevel)s",
     "%(senderName)s changed the power level of %(powerLevelDiffText)s.": "%(senderName)s changed the power level of %(powerLevelDiffText)s.",
     "%(senderName)s changed the pinned messages for the room.": "%(senderName)s changed the pinned messages for the room.",