diff --git a/dom/performance/Performance.h b/dom/performance/Performance.h
index cf26f3206493..adf1c00e52e7 100644
--- a/dom/performance/Performance.h
+++ b/dom/performance/Performance.h
@@ -149,6 +149,8 @@ class Performance : public DOMEventTargetHelper {
 
   virtual class EventCounts* EventCounts() = 0;
 
+  virtual uint64_t InteractionCount() = 0;
+
   virtual void QueueNavigationTimingEntry() = 0;
 
   virtual void UpdateNavigationTimingEntry() = 0;
diff --git a/dom/performance/PerformanceInteractionMetrics.h b/dom/performance/PerformanceInteractionMetrics.h
index e0751be5a78e..71d0b6060a26 100644
--- a/dom/performance/PerformanceInteractionMetrics.h
+++ b/dom/performance/PerformanceInteractionMetrics.h
@@ -30,6 +30,8 @@ class PerformanceInteractionMetrics final {
     return mPendingPointerDowns;
   }
 
+  uint64_t InteractionCount() { return mInteractionCount; }
+
   uint64_t IncreaseInteractionValueAndCount();
 
   virtual ~PerformanceInteractionMetrics() = default;
diff --git a/dom/performance/PerformanceMainThread.cpp b/dom/performance/PerformanceMainThread.cpp
index 6c4b3941e714..b6d5bcaa4247 100644
--- a/dom/performance/PerformanceMainThread.cpp
+++ b/dom/performance/PerformanceMainThread.cpp
@@ -559,6 +559,11 @@ EventCounts* PerformanceMainThread::EventCounts() {
   return mEventCounts;
 }
 
+uint64_t PerformanceMainThread::InteractionCount() {
+  MOZ_ASSERT(StaticPrefs::dom_performance_event_timing_enable_interactionid());
+  return mInteractionMetrics.InteractionCount();
+}
+
 void PerformanceMainThread::GetEntries(
     nsTArray<RefPtr<PerformanceEntry>>& aRetval) {
   aRetval = mResourceEntries.Clone();
diff --git a/dom/performance/PerformanceMainThread.h b/dom/performance/PerformanceMainThread.h
index 2040f98348a1..a25a108d1579 100644
--- a/dom/performance/PerformanceMainThread.h
+++ b/dom/performance/PerformanceMainThread.h
@@ -114,6 +114,8 @@ class PerformanceMainThread final : public Performance,
 
   class EventCounts* EventCounts() override;
 
+  uint64_t InteractionCount() override;
+
   bool IsGlobalObjectWindow() const override { return true; };
 
   bool HasDispatchedInputEvent() const { return mHasDispatchedInputEvent; }
diff --git a/dom/performance/PerformanceWorker.h b/dom/performance/PerformanceWorker.h
index 2c3d8d4d475a..867042a52ac6 100644
--- a/dom/performance/PerformanceWorker.h
+++ b/dom/performance/PerformanceWorker.h
@@ -90,6 +90,10 @@ class PerformanceWorker final : public Performance {
     MOZ_CRASH("This should not be called on workers");
   }
 
+  uint64_t InteractionCount() override {
+    MOZ_CRASH("This should not be called on workers");
+  }
+
  protected:
   ~PerformanceWorker();
 
diff --git a/dom/webidl/Performance.webidl b/dom/webidl/Performance.webidl
index f8ea8dfdc9b7..06ae9fa4fc91 100644
--- a/dom/webidl/Performance.webidl
+++ b/dom/webidl/Performance.webidl
@@ -94,4 +94,7 @@ partial interface Performance {
 partial interface Performance {
   [Pref="dom.enable_event_timing", SameObject]
   readonly attribute EventCounts eventCounts;
+
+  [Pref="dom.performance.event_timing.enable_interactionid"]
+  readonly attribute unsigned long long interactionCount;
 };
diff --git a/testing/web-platform/meta/event-timing/idlharness.any.js.ini b/testing/web-platform/meta/event-timing/idlharness.any.js.ini
index d088a3c14e1a..3700a39fed0e 100644
--- a/testing/web-platform/meta/event-timing/idlharness.any.js.ini
+++ b/testing/web-platform/meta/event-timing/idlharness.any.js.ini
@@ -4,12 +4,6 @@
     if os == "win": [OK, TIMEOUT]
 
 [idlharness.any.html]
-  [Performance interface: attribute interactionCount]
-    expected: FAIL
-
-  [Performance interface: performance must inherit property "interactionCount" with the proper type]
-    expected: FAIL
-
 
 [idlharness.any.sharedworker.html]
 
diff --git a/testing/web-platform/meta/event-timing/idlharness.window.js.ini b/testing/web-platform/meta/event-timing/idlharness.window.js.ini
deleted file mode 100644
index 7602771fe7fb..000000000000
--- a/testing/web-platform/meta/event-timing/idlharness.window.js.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[idlharness.window.html]
-  [Performance interface: attribute interactionCount]
-    expected: FAIL
-
-  [Performance interface: performance must inherit property "interactionCount" with the proper type]
-    expected: FAIL
diff --git a/testing/web-platform/meta/event-timing/interaction-count-click.html.ini b/testing/web-platform/meta/event-timing/interaction-count-click.html.ini
deleted file mode 100644
index 4c4b090ba2ce..000000000000
--- a/testing/web-platform/meta/event-timing/interaction-count-click.html.ini
+++ /dev/null
@@ -1,8 +0,0 @@
-[interaction-count-click.html]
-  expected:
-    if debug and (os == "win") and (processor == "x86_64"): CRASH
-    if debug and (os == "linux") and fission: CRASH
-    if debug and (os == "android"): CRASH
-    if not debug and (os == "android"): [OK, CRASH]
-  [EventTiming: verify interactionCount for click interaction]
-    expected: FAIL
diff --git a/testing/web-platform/meta/event-timing/interaction-count-tap.html.ini b/testing/web-platform/meta/event-timing/interaction-count-tap.html.ini
deleted file mode 100644
index 3881e883662d..000000000000
--- a/testing/web-platform/meta/event-timing/interaction-count-tap.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[interaction-count-tap.html]
-  [EventTiming: verify interactionCount for tap interaction]
-    expected: FAIL