diff --git a/gfx/layers/apz/src/AsyncPanZoomAnimation.h b/gfx/layers/apz/src/AsyncPanZoomAnimation.h
index 575e1b68e532..127667afd949 100644
--- a/gfx/layers/apz/src/AsyncPanZoomAnimation.h
+++ b/gfx/layers/apz/src/AsyncPanZoomAnimation.h
@@ -81,6 +81,8 @@ class AsyncPanZoomAnimation {
 
   virtual void Cancel(CancelAnimationFlags aFlags) {}
 
+  virtual bool WasTriggeredByScript() const { return false; }
+
  protected:
   // Protected destructor, to discourage deletion outside of Release():
   virtual ~AsyncPanZoomAnimation() = default;
diff --git a/gfx/layers/apz/src/AsyncPanZoomController.cpp b/gfx/layers/apz/src/AsyncPanZoomController.cpp
index 265331d52734..3cb4c00e53eb 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -1995,7 +1995,7 @@ nsEventStatus AsyncPanZoomController::OnKeyboard(const KeyboardInput& aEvent) {
     // existing smooth scroll animation if there is one.
     APZC_LOG("%p keyboard scrolling to snap point %s\n", this,
              ToString(destination).c_str());
-    SmoothMsdScrollTo(destination);
+    SmoothMsdScrollTo(destination, ScrollTriggeredByScript::No);
     return nsEventStatus_eConsumeDoDefault;
   }
 
@@ -2408,7 +2408,7 @@ nsEventStatus AsyncPanZoomController::OnScrollWheel(
         // existing smooth scroll animation if there is one.
         APZC_LOG("%p wheel scrolling to snap point %s\n", this,
                  ToString(startPosition).c_str());
-        SmoothMsdScrollTo(startPosition);
+        SmoothMsdScrollTo(startPosition, ScrollTriggeredByScript::No);
         break;
       }
 
@@ -3719,12 +3719,13 @@ void AsyncPanZoomController::SmoothScrollTo(const CSSPoint& aDestination,
   StartAnimation(animation.get());
 }
 
-void AsyncPanZoomController::SmoothMsdScrollTo(const CSSPoint& aDestination) {
+void AsyncPanZoomController::SmoothMsdScrollTo(
+    const CSSPoint& aDestination, ScrollTriggeredByScript aTriggeredByScript) {
   if (mState == SMOOTHMSD_SCROLL && mAnimation) {
     APZC_LOG("%p updating destination on existing animation\n", this);
     RefPtr<SmoothMsdScrollAnimation> animation(
         static_cast<SmoothMsdScrollAnimation*>(mAnimation.get()));
-    animation->SetDestination(aDestination);
+    animation->SetDestination(aDestination, aTriggeredByScript);
   } else {
     CancelAnimation();
     SetState(SMOOTHMSD_SCROLL);
@@ -3739,7 +3740,8 @@ void AsyncPanZoomController::SmoothMsdScrollTo(const CSSPoint& aDestination) {
     StartAnimation(new SmoothMsdScrollAnimation(
         *this, Metrics().GetVisualScrollOffset(), initialVelocity, aDestination,
         StaticPrefs::layout_css_scroll_behavior_spring_constant(),
-        StaticPrefs::layout_css_scroll_behavior_damping_ratio()));
+        StaticPrefs::layout_css_scroll_behavior_damping_ratio(),
+        aTriggeredByScript));
   }
 }
 
@@ -5123,9 +5125,11 @@ void AsyncPanZoomController::NotifyLayersUpdated(
       }
 
       if (scrollUpdate.GetMode() == ScrollMode::SmoothMsd) {
-        SmoothMsdScrollTo(destination);
+        SmoothMsdScrollTo(destination,
+                          scrollUpdate.GetScrollTriggeredByScript());
       } else {
         MOZ_ASSERT(scrollUpdate.GetMode() == ScrollMode::Smooth);
+        MOZ_ASSERT(!scrollUpdate.WasTriggeredByScript());
         SmoothScrollTo(destination, scrollUpdate.GetOrigin());
       }
       continue;
@@ -5907,7 +5911,7 @@ void AsyncPanZoomController::ScrollSnapNear(const CSSPoint& aDestination) {
     if (*snapPoint != Metrics().GetVisualScrollOffset()) {
       APZC_LOG("%p smooth scrolling to snap point %s\n", this,
                ToString(*snapPoint).c_str());
-      SmoothMsdScrollTo(*snapPoint);
+      SmoothMsdScrollTo(*snapPoint, ScrollTriggeredByScript::No);
     }
   }
 }
@@ -5953,7 +5957,7 @@ void AsyncPanZoomController::ScrollSnapToDestination() {
         (float)Metrics().GetVisualScrollOffset().y, (float)startPosition.x,
         (float)startPosition.y);
 
-    SmoothMsdScrollTo(startPosition);
+    SmoothMsdScrollTo(startPosition, ScrollTriggeredByScript::No);
   }
 }
 
diff --git a/gfx/layers/apz/src/AsyncPanZoomController.h b/gfx/layers/apz/src/AsyncPanZoomController.h
index e35fbaf1f17a..ebb8e98b4089 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.h
+++ b/gfx/layers/apz/src/AsyncPanZoomController.h
@@ -1483,7 +1483,8 @@ class AsyncPanZoomController {
 
   // Start a smooth-scrolling animation to the given destination, with MSD
   // physics that is suited for scroll-snapping.
-  void SmoothMsdScrollTo(const CSSPoint& aDestination);
+  void SmoothMsdScrollTo(const CSSPoint& aDestination,
+                         ScrollTriggeredByScript aTriggeredByScript);
 
   // Returns whether overscroll is allowed during an event.
   bool AllowScrollHandoffInCurrentBlock() const;
diff --git a/gfx/layers/apz/src/SmoothMsdScrollAnimation.cpp b/gfx/layers/apz/src/SmoothMsdScrollAnimation.cpp
index 03d4850b498c..dc9d5e544518 100644
--- a/gfx/layers/apz/src/SmoothMsdScrollAnimation.cpp
+++ b/gfx/layers/apz/src/SmoothMsdScrollAnimation.cpp
@@ -12,12 +12,14 @@ namespace layers {
 SmoothMsdScrollAnimation::SmoothMsdScrollAnimation(
     AsyncPanZoomController& aApzc, const CSSPoint& aInitialPosition,
     const CSSPoint& aInitialVelocity, const CSSPoint& aDestination,
-    double aSpringConstant, double aDampingRatio)
+    double aSpringConstant, double aDampingRatio,
+    ScrollTriggeredByScript aTriggeredByScript)
     : mApzc(aApzc),
       mXAxisModel(aInitialPosition.x, aDestination.x, aInitialVelocity.x,
                   aSpringConstant, aDampingRatio),
       mYAxisModel(aInitialPosition.y, aDestination.y, aInitialVelocity.y,
-                  aSpringConstant, aDampingRatio) {}
+                  aSpringConstant, aDampingRatio),
+      mTriggeredByScript(aTriggeredByScript) {}
 
 bool SmoothMsdScrollAnimation::DoSample(FrameMetrics& aFrameMetrics,
                                         const TimeDuration& aDelta) {
@@ -113,9 +115,12 @@ bool SmoothMsdScrollAnimation::DoSample(FrameMetrics& aFrameMetrics,
   return true;
 }
 
-void SmoothMsdScrollAnimation::SetDestination(const CSSPoint& aNewDestination) {
+void SmoothMsdScrollAnimation::SetDestination(
+    const CSSPoint& aNewDestination,
+    ScrollTriggeredByScript aTriggeredByScript) {
   mXAxisModel.SetDestination(aNewDestination.x);
   mYAxisModel.SetDestination(aNewDestination.y);
+  mTriggeredByScript = aTriggeredByScript;
 }
 
 CSSPoint SmoothMsdScrollAnimation::GetDestination() const {
diff --git a/gfx/layers/apz/src/SmoothMsdScrollAnimation.h b/gfx/layers/apz/src/SmoothMsdScrollAnimation.h
index 956672a03fca..dc105d77019e 100644
--- a/gfx/layers/apz/src/SmoothMsdScrollAnimation.h
+++ b/gfx/layers/apz/src/SmoothMsdScrollAnimation.h
@@ -9,19 +9,21 @@
 
 #include "AsyncPanZoomAnimation.h"
 #include "mozilla/layers/AxisPhysicsMSDModel.h"
+#include "mozilla/ScrollPositionUpdate.h"
 
 namespace mozilla {
 namespace layers {
 
 class AsyncPanZoomController;
 
-class SmoothMsdScrollAnimation : public AsyncPanZoomAnimation {
+class SmoothMsdScrollAnimation final : public AsyncPanZoomAnimation {
  public:
   SmoothMsdScrollAnimation(AsyncPanZoomController& aApzc,
                            const CSSPoint& aInitialPosition,
                            const CSSPoint& aInitialVelocity,
                            const CSSPoint& aDestination, double aSpringConstant,
-                           double aDampingRatio);
+                           double aDampingRatio,
+                           ScrollTriggeredByScript aTriggeredByScript);
 
   /**
    * Advances a smooth scroll simulation based on the time passed in |aDelta|.
@@ -32,14 +34,20 @@ class SmoothMsdScrollAnimation : public AsyncPanZoomAnimation {
   bool DoSample(FrameMetrics& aFrameMetrics,
                 const TimeDuration& aDelta) override;
 
-  void SetDestination(const CSSPoint& aNewDestination);
+  void SetDestination(const CSSPoint& aNewDestination,
+                      ScrollTriggeredByScript aTriggeredByScript);
   CSSPoint GetDestination() const;
   SmoothMsdScrollAnimation* AsSmoothMsdScrollAnimation() override;
 
+  bool WasTriggeredByScript() const override {
+    return mTriggeredByScript == ScrollTriggeredByScript::Yes;
+  }
+
  private:
   AsyncPanZoomController& mApzc;
   AxisPhysicsMSDModel mXAxisModel;
   AxisPhysicsMSDModel mYAxisModel;
+  ScrollTriggeredByScript mTriggeredByScript;
 };
 
 }  // namespace layers