diff --git a/packages/react-native/src/private/webapis/performance/Performance.js b/packages/react-native/src/private/webapis/performance/Performance.js
index 2447879e619..8ac0054fd0a 100644
--- a/packages/react-native/src/private/webapis/performance/Performance.js
+++ b/packages/react-native/src/private/webapis/performance/Performance.js
@@ -116,13 +116,15 @@ export default class Performance {
         markOptions?.startTime,
       );
     } else if (NativePerformance?.mark) {
-      NativePerformance.mark(markName, markOptions?.startTime);
+      computedStartTime = markOptions?.startTime ?? performance.now();
+      NativePerformance?.mark?.(markName, computedStartTime);
     } else {
       warnNoNativePerformance();
+      computedStartTime = performance.now();
     }
 
     return new PerformanceMark(markName, {
-      startTime: computedStartTime ?? performance.now(),
+      startTime: computedStartTime,
       detail: markOptions?.detail,
     });
   }
diff --git a/packages/react-native/src/private/webapis/performance/specs/NativePerformance.js b/packages/react-native/src/private/webapis/performance/specs/NativePerformance.js
index 85fa3ccd01b..aa10bbd706c 100644
--- a/packages/react-native/src/private/webapis/performance/specs/NativePerformance.js
+++ b/packages/react-native/src/private/webapis/performance/specs/NativePerformance.js
@@ -46,7 +46,7 @@ export type PerformanceObserverInit = {
 export interface Spec extends TurboModule {
   +now?: () => number;
   // TODO: remove when `markWithResult` is fully rolled out.
-  +mark?: (name: string, startTime?: number) => void;
+  +mark?: (name: string, startTime: number) => void;
   // TODO: remove when `measureWithResult` is fully rolled out.
   +measure?: (
     name: string,