diff --git a/addons/xterm-addon-ligatures/src/index.ts b/addons/xterm-addon-ligatures/src/index.ts
index c54f3b5048..058d9454d8 100644
--- a/addons/xterm-addon-ligatures/src/index.ts
+++ b/addons/xterm-addon-ligatures/src/index.ts
@@ -54,7 +54,7 @@ export function enableLigatures(term: Terminal): void {
 
             // Only refresh things if we actually found a font
             if (f) {
-              term.refresh(0, term.options.rows! - 1);
+              term.refresh(0, term.rows - 1);
             }
           }
         })
diff --git a/test/api/TestUtils.ts b/test/api/TestUtils.ts
index 5731009b79..3fd0648eb4 100644
--- a/test/api/TestUtils.ts
+++ b/test/api/TestUtils.ts
@@ -5,7 +5,7 @@
 
 import * as playwright from 'playwright';
 import deepEqual = require('deep-equal');
-import { ITerminalOptions } from 'xterm';
+import { ITerminalInitOnlyOptions, ITerminalOptions } from 'xterm';
 import { deepStrictEqual, fail } from 'assert';
 
 export async function pollFor<T>(page: playwright.Page, evalOrFn: string | (() => Promise<T>), val: T, preFn?: () => Promise<void>, maxDuration?: number): Promise<void> {
@@ -43,7 +43,7 @@ export async function timeout(ms: number): Promise<void> {
   return new Promise<void>(r => setTimeout(r, ms));
 }
 
-export async function openTerminal(page: playwright.Page, options: ITerminalOptions = {}): Promise<void> {
+export async function openTerminal(page: playwright.Page, options: ITerminalOptions & ITerminalInitOnlyOptions = {}): Promise<void> {
   await page.evaluate(`window.term = new Terminal(${JSON.stringify({ allowProposedApi: true, ...options })})`);
   await page.evaluate(`window.term.open(document.querySelector('#terminal-container'))`);
   await page.waitForSelector('.xterm-rows');
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index 8c4e7735f6..6619d4e6d9 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -21,7 +21,7 @@ declare module 'xterm' {
   export type LogLevel = 'debug' | 'info' | 'warn' | 'error' | 'off';
 
   /**
-   * An object containing start up options for the terminal.
+   * An object containing options for the terminal.
    */
   export interface ITerminalOptions {
     /**
@@ -55,11 +55,6 @@ declare module 'xterm' {
      */
     convertEol?: boolean;
 
-    /**
-     * The number of columns in the terminal.
-     */
-    cols?: number;
-
     /**
      * Whether the cursor blinks.
      */
@@ -177,11 +172,6 @@ declare module 'xterm' {
      */
     rightClickSelectsWord?: boolean;
 
-    /**
-     * The number of rows in the terminal.
-     */
-    rows?: number;
-
     /**
      * Whether screen reader support is enabled. When on this will expose
      * supporting elements in the DOM to support NVDA on Windows and VoiceOver
@@ -248,6 +238,22 @@ declare module 'xterm' {
     overviewRulerWidth?: number;
   }
 
+  /**
+   * An object containing additional options for the terminal that can only be
+   * set on start up.
+   */
+  export interface ITerminalInitOnlyOptions {
+    /**
+     * The number of columns in the terminal.
+     */
+    cols?: number;
+
+    /**
+     * The number of rows in the terminal.
+     */
+    rows?: number;
+  }
+
   /**
    * Contains colors to theme the terminal with.
    */
@@ -714,7 +720,7 @@ declare module 'xterm' {
      *
      * @param options An object containing a set of options.
      */
-    constructor(options?: ITerminalOptions);
+    constructor(options?: ITerminalOptions & ITerminalInitOnlyOptions);
 
     /**
      * Adds an event listener for when the bell is triggered.