diff --git a/lib/frontend/actions/events.js b/lib/frontend/actions/events.js
index 60d41b4..136ae15 100644
--- a/lib/frontend/actions/events.js
+++ b/lib/frontend/actions/events.js
@@ -1,7 +1,12 @@
 import { postURL } from '../services'
 import { eventStore, parseStatusStore, requestStore } from '../stores'
 import { Request } from '../records'
-import { uuidv4, parseStartTimeFromiCalString, promptDownload } from '../utils'
+import {
+  uuidv4,
+  parseStartTimeFromiCalString,
+  promptDownload,
+  encodeIcalString,
+} from '../utils'
 import { extractEventDataFromHTML } from '../../../lib/services/ics-retriever'
 import generateICS from '../../../lib/services/ics-generator'
 
@@ -35,7 +40,7 @@ const createICS = async (html, url, { logger }) => {
 
     const eventData = extractEventDataFromHTML(html, url, { logger })
     const text = await generateICS(eventData)
-    const dataUri = encodeURIComponent(text)
+    const dataUri = encodeIcalString(text)
     const uri = `data:text/calendar;charset=utf-8,${dataUri}`
 
     const summaryMatch = text.match(/SUMMARY:.*/)[0]
diff --git a/lib/frontend/utils.js b/lib/frontend/utils.js
index 9abeb83..68032e3 100644
--- a/lib/frontend/utils.js
+++ b/lib/frontend/utils.js
@@ -1,3 +1,5 @@
+const UNICODE_RE = /[\ud800-\udbff][\udc00-\udfff]|[\ud800-\udfff]/g
+
 export const migrateRecord = (record) => {
   // NOTE: v3 records
   const id = record.id || record.order
@@ -55,3 +57,13 @@ export const promptDownload = (uri) => {
 
   link.setAttribute('href', '')
 }
+
+export const encodeIcalString = (string) => {
+  try {
+    return encodeURIComponent(string)
+  } catch {
+    return string.replace(UNICODE_RE , ($0) => {
+      return $0.length > 1 ? $0 : '\ufffd';
+    })
+  }
+}