diff --git a/src/browser/public/Terminal.ts b/src/browser/public/Terminal.ts
index 9571afa66..1acde934d 100644
--- a/src/browser/public/Terminal.ts
+++ b/src/browser/public/Terminal.ts
@@ -166,7 +166,7 @@ export class Terminal implements ITerminalApi {
     this._checkProposedApi();
     this._core.deregisterCharacterJoiner(joinerId);
   }
-  public registerMarker(cursorYOffset: number): IMarker | undefined {
+  public registerMarker(cursorYOffset: number = 0): IMarker | undefined {
     this._checkProposedApi();
     this._verifyIntegers(cursorYOffset);
     return this._core.addMarker(cursorYOffset);
diff --git a/src/headless/public/Terminal.ts b/src/headless/public/Terminal.ts
index 9aa171a45..5a35fae29 100644
--- a/src/headless/public/Terminal.ts
+++ b/src/headless/public/Terminal.ts
@@ -136,7 +136,7 @@ export class Terminal implements ITerminalApi {
     this._verifyIntegers(columns, rows);
     this._core.resize(columns, rows);
   }
-  public registerMarker(cursorYOffset: number): IMarker | undefined {
+  public registerMarker(cursorYOffset: number = 0): IMarker | undefined {
     this._checkProposedApi();
     this._verifyIntegers(cursorYOffset);
     return this._core.addMarker(cursorYOffset);
diff --git a/typings/xterm-headless.d.ts b/typings/xterm-headless.d.ts
index 6d2b3e270..0ab8bd960 100644
--- a/typings/xterm-headless.d.ts
+++ b/typings/xterm-headless.d.ts
@@ -643,7 +643,7 @@ declare module 'xterm-headless' {
      * @param cursorYOffset The y position offset of the marker from the cursor.
      * @returns The new marker or undefined.
      */
-    registerMarker(cursorYOffset: number): IMarker | undefined;
+    registerMarker(cursorYOffset?: number): IMarker | undefined;
 
     /**
      * @deprecated use `registerMarker` instead.
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index 17bf8d501..2cd4daa61 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -930,7 +930,7 @@ declare module 'xterm' {
      * @param cursorYOffset The y position offset of the marker from the cursor.
      * @returns The new marker or undefined.
      */
-    registerMarker(cursorYOffset: number): IMarker | undefined;
+    registerMarker(cursorYOffset?: number): IMarker | undefined;
 
     /**
      * @deprecated use `registerMarker` instead.