diff --git a/src/components/views/elements/Pill.tsx b/src/components/views/elements/Pill.tsx
index 67d0f6d6d6..965205e71f 100644
--- a/src/components/views/elements/Pill.tsx
+++ b/src/components/views/elements/Pill.tsx
@@ -37,8 +37,8 @@ export enum PillType {
     EventInOtherRoom = "TYPE_EVENT_IN_OTHER_ROOM",
 }
 
-export const pillRoomNotifPos = (text: string): number => {
-    return text.indexOf("@room");
+export const pillRoomNotifPos = (text: string | null): number => {
+    return text?.indexOf("@room") ?? -1;
 };
 
 export const pillRoomNotifLen = (): number => {
diff --git a/src/utils/permalinks/Permalinks.ts b/src/utils/permalinks/Permalinks.ts
index d2981905e3..caae2eb6c3 100644
--- a/src/utils/permalinks/Permalinks.ts
+++ b/src/utils/permalinks/Permalinks.ts
@@ -84,9 +84,9 @@ const ANY_REGEX = /.*/;
 export class RoomPermalinkCreator {
     private roomId: string;
     private highestPlUserId: string | null = null;
-    private populationMap: { [serverName: string]: number } | null = null;
-    private bannedHostsRegexps: RegExp[] | null = null;
-    private allowedHostsRegexps: RegExp[] | null = null;
+    private populationMap: { [serverName: string]: number } = {};
+    private bannedHostsRegexps: RegExp[] = [];
+    private allowedHostsRegexps: RegExp[] = [];
     private _serverCandidates?: string[];
     private started = false;
 
diff --git a/src/utils/pillify.tsx b/src/utils/pillify.tsx
index e1f001eb91..5d52ea53b9 100644
--- a/src/utils/pillify.tsx
+++ b/src/utils/pillify.tsx
@@ -82,7 +82,7 @@ export function pillifyLinks(nodes: ArrayLike<Element>, mxEvent: MatrixEvent, pi
                 );
 
                 ReactDOM.render(pill, pillContainer);
-                node.parentNode.replaceChild(pillContainer, node);
+                node.parentNode?.replaceChild(pillContainer, node);
                 pills.push(pillContainer);
                 // Pills within pills aren't going to go well, so move on
                 pillified = true;
@@ -95,10 +95,10 @@ export function pillifyLinks(nodes: ArrayLike<Element>, mxEvent: MatrixEvent, pi
             // as applying pills happens outside of react, make sure we're not doubly
             // applying @room pills here, as a rerender with the same content won't touch the DOM
             // to clear the pills from the last run of pillifyLinks
-            !node.parentElement.classList.contains("mx_AtRoomPill")
+            !node.parentElement?.classList.contains("mx_AtRoomPill")
         ) {
             let currentTextNode = node as Node as Text | null;
-            const roomNotifTextNodes = [];
+            const roomNotifTextNodes: Text[] = [];
 
             // Take a textNode and break it up to make all the instances of @room their
             // own textNode, adding those nodes to roomNotifTextNodes
@@ -109,7 +109,7 @@ export function pillifyLinks(nodes: ArrayLike<Element>, mxEvent: MatrixEvent, pi
                     let roomTextNode = currentTextNode;
 
                     if (roomNotifPos > 0) roomTextNode = roomTextNode.splitText(roomNotifPos);
-                    if (roomTextNode.textContent.length > pillRoomNotifLen()) {
+                    if (roomTextNode.textContent && roomTextNode.textContent.length > pillRoomNotifLen()) {
                         nextTextNode = roomTextNode.splitText(pillRoomNotifLen());
                     }
                     roomNotifTextNodes.push(roomTextNode);
@@ -140,7 +140,7 @@ export function pillifyLinks(nodes: ArrayLike<Element>, mxEvent: MatrixEvent, pi
                         );
 
                         ReactDOM.render(pill, pillContainer);
-                        roomNotifTextNode.parentNode.replaceChild(pillContainer, roomNotifTextNode);
+                        roomNotifTextNode.parentNode?.replaceChild(pillContainer, roomNotifTextNode);
                         pills.push(pillContainer);
                     }
                     // Nothing else to do for a text node (and we don't need to advance