diff --git a/src/InputHandler.ts b/src/InputHandler.ts
index 574d29b8..259a2b1c 100644
--- a/src/InputHandler.ts
+++ b/src/InputHandler.ts
@@ -2094,7 +2094,7 @@ export class InputHandler extends Disposable implements IInputHandler {
         if (rs) {
           const w = rs.dimensions.actualCellWidth.toFixed(0);
           const h = rs.dimensions.actualCellHeight.toFixed(0);
-          this._coreService.triggerDataEvent(`${C0.ESC}[4;${h};${w}t`);
+          this._coreService.triggerDataEvent(`${C0.ESC}[6;${h};${w}t`);
         }
         break;
       case 18:  // GetWinSizeChars, returns CSI 8 ; height ; width t
diff --git a/test/api/InputHandler.api.ts b/test/api/InputHandler.api.ts
index fe068610..991c5cb5 100644
--- a/test/api/InputHandler.api.ts
+++ b/test/api/InputHandler.api.ts
@@ -346,6 +346,51 @@ describe('InputHandler Integration Tests', function(): void {
       `);
       assert.deepEqual(await getLinesAsArray(3), ['#', ' #', 'abcd####']);
     });
+
+    describe.only('Window Options - CSI Ps ; Ps ; Ps t', () => {
+      it('should be disabled by default', async function() {
+        assert.equal(await page.evaluate(`(() => window.term.getOption('allowedWindowOps'))()`), '');
+        await page.evaluate(`(() => {
+          window._stack = [];
+          const _h = window.term.onData(data => window._stack.push(data));
+          window.term.write('\x1b[14t');
+          window.term.write('\x1b[16t');
+          window.term.write('\x1b[18t');
+          window.term.write('\x1b[20t');
+          window.term.write('\x1b[21t');
+          return new Promise((r) => window.term.write('', () => { _h.dispose(); r(); }));
+        })()`);
+        assert.deepEqual(await page.evaluate(`(() => _stack)()`), []);
+      });
+      it('14 - GetWinSizePixels', async function() {
+        assert.equal(await page.evaluate(`(() => {
+          window.term.setOption('allowedWindowOps', 'GetWinSizePixels');
+          return window.term.getOption('allowedWindowOps');
+        })()`), '14');
+        await page.evaluate(`(() => {
+          window._stack = [];
+          const _h = window.term.onData(data => window._stack.push(data));
+          window.term.write('\x1b[14t');
+          return new Promise((r) => window.term.write('', () => { _h.dispose(); r(); }));
+        })()`);
+        const d = await getDimensions();
+        assert.deepEqual(await page.evaluate(`(() => _stack)()`), [`\x1b[4;${d.height};${d.width}t`]);
+      });
+      it('16 - GetCellSizePixels', async function() {
+        assert.equal(await page.evaluate(`(() => {
+          window.term.setOption('allowedWindowOps', 'GetCellSizePixels');
+          return window.term.getOption('allowedWindowOps');
+        })()`), '16');
+        await page.evaluate(`(() => {
+          window._stack = [];
+          const _h = window.term.onData(data => window._stack.push(data));
+          window.term.write('\x1b[16t');
+          return new Promise((r) => window.term.write('', () => { _h.dispose(); r(); }));
+        })()`);
+        const d = await getDimensions();
+        assert.deepEqual(await page.evaluate(`(() => _stack)()`), [`\x1b[6;${d.cellHeight};${d.cellWidth}t`]);
+      });
+    });
   });
 
   describe('ESC', () => {
@@ -404,3 +449,17 @@ async function getCursor(): Promise<{col: number, row: number}> {
   })();
   `);
 }
+
+async function getDimensions(): Promise<any> {
+  const dim = await page.evaluate(`
+    (function() {
+      return term._core._renderService.dimensions;
+    })();
+  `);
+  return {
+    cellWidth: dim.actualCellWidth.toFixed(0),
+    cellHeight: dim.actualCellHeight.toFixed(0),
+    width: dim.canvasWidth.toFixed(0),
+    height: dim.canvasHeight.toFixed(0)
+  };
+}