angular
diff --git a/‎src/compat/performance/performance.service.ts
+2-2 b/‎src/compat/performance/performance.service.ts
+2-2
diff --git a/‎src/compat/performance/performance.ts
+1-1 b/‎src/compat/performance/performance.ts
+1-1
@@ -6,7 +6,7 @@ const IS_STABLE_START_MARK = '_isStableStart';
 const IS_STABLE_END_MARK = '_isStableEnd';
 
 function markStarts() {
-    if (typeof(window) !== 'undefined' && window.performance) {
+    if (typeof(window) !== 'undefined' && window.performance && window.performance.mark) {
         window.performance.mark(IS_STABLE_START_MARK);
         return true;
     } else {
@@ -22,7 +22,7 @@ export class PerformanceMonitoringService implements OnDestroy {
     private disposable: Subscription|undefined;
 
     constructor(appRef: ApplicationRef) {
-        if (started) {
+        if (started && window.performance.mark) {
             this.disposable = appRef.isStable.pipe(
                 first(it => it),
                 tap(() => {
 
@@ -52,7 +52,7 @@ export class AngularFirePerformance {
 }
 
 const trace$ = (traceId: string) => {
-  if (typeof window !== 'undefined' && window.performance) {
+  if (typeof window !== 'undefined' && window.performance && window.performance.mark) {
     const entries = window.performance.getEntriesByName(traceId, 'measure') || [];
     const startMarkName = `_${traceId}Start[${entries.length}]`;
     const endMarkName = `_${traceId}End[${entries.length}]`;
Original file line number	Diff line number	Diff line change
`@@ -52,7 +52,7 @@ export class AngularFirePerformance {`
`52`	`52`	`}`
`53`	`53`
`54`	`54`	`const trace$ = (traceId: string) => {`
`55`		`- if (typeof window !== 'undefined' && window.performance) {`
	`55`	`+ if (typeof window !== 'undefined' && window.performance && window.performance.mark) {`
`56`	`56`	`const entries = window.performance.getEntriesByName(traceId, 'measure') \|\| [];`
`57`	`57`	const startMarkName = `_${traceId}Start[${entries.length}]`;
`58`	`58`	const endMarkName = `_${traceId}End[${entries.length}]`;