diff --git a/types/phoenix/index.d.ts b/types/phoenix/index.d.ts
index 22a4d25f40..526b970e48 100644
--- a/types/phoenix/index.d.ts
+++ b/types/phoenix/index.d.ts
@@ -36,18 +36,21 @@ export class Channel {
   push(event: string, payload: object, timeout?: number): Push;
 }
 
+export type BinaryType = 'arraybuffer' | 'blob';
 export type ConnectionState = 'connecting' | 'open' | 'closing' | 'closed';
 
 export interface SocketConnectOption {
+  binaryType: BinaryType;
   params: object | (() => object);
   transport: string;
   timeout: number;
   heartbeatIntervalMs: number;
-  reconnectAfterMs: number;
   longpollerTimeout: number;
   encode: (payload: object, callback: (encoded: any) => void) => void;
   decode: (payload: string, callback: (decoded: any) => void) => void;
   logger: (kind: string, message: string, data: any) => void;
+  reconnectAfterMs: (tries: number) => number;
+  rejoinAfterMs: (tries: number) => number;
 }
 
 export class Socket {
diff --git a/types/phoenix/phoenix-tests.ts b/types/phoenix/phoenix-tests.ts
index f0b0937851..86da971e05 100644
--- a/types/phoenix/phoenix-tests.ts
+++ b/types/phoenix/phoenix-tests.ts
@@ -1,7 +1,12 @@
 import { Socket, Channel, Presence } from 'phoenix';
 
 function test_socket() {
-  const socket = new Socket('/ws', {params: {userToken: '123'}});
+  const socket = new Socket('/ws', {
+      binaryType: 'arraybuffer',
+      params: { userToken: '123' },
+      reconnectAfterMs: tries => 1000,
+      rejoinAfterMs: tries => 1000,
+  });
   socket.connect();
 }