diff --git a/src/models/room-member.ts b/src/models/room-member.ts
index e7a98257b..e3d6b66ce 100644
--- a/src/models/room-member.ts
+++ b/src/models/room-member.ts
@@ -131,7 +131,11 @@ export class RoomMember extends EventEmitter {
             this.disambiguate,
         );
 
-        this.rawDisplayName = event.getDirectionalContent().displayname || this.userId;
+        this.rawDisplayName = event.getDirectionalContent().displayname;
+        if (!this.rawDisplayName || !utils.removeHiddenChars(this.rawDisplayName)) {
+            this.rawDisplayName = this.userId;
+        }
+
         if (oldMembership !== this.membership) {
             this.updateModifiedTime();
             this.emit("RoomMember.membership", event, this, oldMembership);
diff --git a/src/utils.ts b/src/utils.ts
index 5abed06af..3b0b9e7b7 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -402,10 +402,11 @@ export function normalize(str: string): string {
 // various width spaces U+2000 - U+200D
 // LTR and RTL marks U+200E and U+200F
 // LTR/RTL and other directional formatting marks U+202A - U+202F
+// Arabic Letter RTL mark U+061C
 // Combining characters U+0300 - U+036F
 // Zero width no-break space (BOM) U+FEFF
 // eslint-disable-next-line no-misleading-character-class
-const removeHiddenCharsRegex = /[\u2000-\u200F\u202A-\u202F\u0300-\u036f\uFEFF\s]/g;
+const removeHiddenCharsRegex = /[\u2000-\u200F\u202A-\u202F\u0300-\u036F\uFEFF\u061C\s]/g;
 
 export function escapeRegExp(string: string): string {
     return string.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");