diff --git a/layout/generic/nsGfxScrollFrame.cpp b/layout/generic/nsGfxScrollFrame.cpp
index 5c0449d5a9b8..339816473da1 100644
--- a/layout/generic/nsGfxScrollFrame.cpp
+++ b/layout/generic/nsGfxScrollFrame.cpp
@@ -2684,6 +2684,20 @@ void ScrollFrameHelper::ScrollToImpl(nsPoint aPt, const nsRect& aRange,
       FrameLayerBuilder::GetPaintedLayerScaleForFrame(mScrolledFrame);
   nsPoint curPos = GetScrollPosition();
 
+  // Below, we clamp |aPt| to the layout scroll range, compare the clamped
+  // value with the current scroll position, and early exit if they are the
+  // same. The early exit bypasses the update of |mLastScrollOrigin|, which
+  // is important to avoid sending a main-thread layout scroll update to APZ,
+  // which can clobber the visual scroll offset as well.
+  // If the layout viewport has shrunk in size since the last scroll, the
+  // clamped target position can be different from the current position, so
+  // we don't take the early exit, but conceptually we still want to avoid
+  // updating |mLastScrollOrigin| and clobbering the visual scroll offset.
+  bool suppressScrollOriginChange = false;
+  if (aPt == curPos) {
+    suppressScrollOriginChange = true;
+  }
+
   nsPoint alignWithPos = mScrollPosForLayerPixelAlignment == nsPoint(-1, -1)
                              ? curPos
                              : mScrollPosForLayerPixelAlignment;
@@ -2759,7 +2773,8 @@ void ScrollFrameHelper::ScrollToImpl(nsPoint aPt, const nsRect& aRange,
   // legitimate scroll offset updates because the origin has been masked by
   // a later change within the same refresh driver tick.
   allowScrollOriginChange =
-      mAllowScrollOriginDowngrade || !isScrollOriginDowngrade;
+      (mAllowScrollOriginDowngrade || !isScrollOriginDowngrade) &&
+      !suppressScrollOriginChange;
 
   if (allowScrollOriginChange) {
     mLastScrollOrigin = aOrigin;