diff --git a/projects/stream-chat-angular/src/lib/read-by.spec.ts b/projects/stream-chat-angular/src/lib/read-by.spec.ts
index ef12eaa9..1d1dd387 100644
--- a/projects/stream-chat-angular/src/lib/read-by.spec.ts
+++ b/projects/stream-chat-angular/src/lib/read-by.spec.ts
@@ -53,4 +53,51 @@ describe('getReadBy', () => {
     expect(result.find((i) => i.id === 'id3')).toBeDefined();
     expect(result.find((i) => i.id === sender.id)).toBeUndefined();
   });
+
+  it('should handle null last_read values gracefully', () => {
+    const sender = { id: 'sender', name: 'Tess' };
+
+    const message = {
+      created_at: new Date('2021-09-14T13:08:30.004112Z'),
+      user: sender,
+    } as FormatMessageResponse;
+
+    const channel = {
+      state: {
+        read: {
+          id1: {
+            last_read: new Date('2021-09-14T13:08:33.004112Z'),
+            user: {
+              id: 'id1',
+              name: 'John',
+            },
+            unread_messages: 2,
+          },
+          id2: {
+            last_read: null,
+            user: {
+              id: 'id2',
+              name: 'Alice',
+            },
+            unread_messages: 2,
+          },
+          id3: {
+            last_read: new Date('2021-09-14T13:08:30.004112Z'),
+            user: {
+              id: 'id3',
+              name: 'Bob',
+            },
+            unread_messages: 2,
+          },
+        },
+      },
+    } as unknown as Channel;
+
+    const result = getReadBy(message, channel);
+
+    expect(result.length).toBe(2);
+    expect(result.find((i) => i.id === 'id1')).toBeDefined();
+    expect(result.find((i) => i.id === 'id3')).toBeDefined();
+    expect(result.find((i) => i.id === 'id2')).toBeUndefined();
+  });
 });
diff --git a/projects/stream-chat-angular/src/lib/read-by.ts b/projects/stream-chat-angular/src/lib/read-by.ts
index 1a6d170c..8646d290 100644
--- a/projects/stream-chat-angular/src/lib/read-by.ts
+++ b/projects/stream-chat-angular/src/lib/read-by.ts
@@ -3,9 +3,10 @@ import { Channel, FormatMessageResponse, UserResponse } from 'stream-chat';
 export const getReadBy = (message: FormatMessageResponse, channel: Channel) => {
   const readBy: UserResponse[] = [];
   Object.keys(channel.state.read).forEach((key) => {
+    const lastRead = channel.state.read[key].last_read;
     if (
-      channel.state.read[key].last_read.getTime() >=
-        message.created_at.getTime() &&
+      lastRead &&
+      lastRead.getTime() >= message.created_at.getTime() &&
       message.user?.id !== key
     ) {
       readBy.push(channel.state.read[key].user);