diff --git a/layout/base/nsDisplayList.cpp b/layout/base/nsDisplayList.cpp
index edad66c30..91d9932d5 100644
--- a/layout/base/nsDisplayList.cpp
+++ b/layout/base/nsDisplayList.cpp
@@ -968,7 +968,6 @@ void
 nsDisplayListBuilder::MarkFramesForDisplayList(nsIFrame* aDirtyFrame,
                                                const nsFrameList& aFrames,
                                                const nsRect& aDirtyRect) {
-  mFramesMarkedForDisplay.SetCapacity(mFramesMarkedForDisplay.Length() + aFrames.GetLength());
   for (nsIFrame* e : aFrames) {
     // Skip the AccessibleCaret frame when building no caret.
     if (!IsBuildingCaret()) {
diff --git a/layout/base/nsDisplayList.h b/layout/base/nsDisplayList.h
index a770da648..ea9398083 100644
--- a/layout/base/nsDisplayList.h
+++ b/layout/base/nsDisplayList.h
@@ -1003,7 +1003,7 @@ private:
   PLArenaPool                    mPool;
   nsCOMPtr<nsISelection>         mBoundingSelection;
   nsAutoTArray<PresShellState,8> mPresShellStates;
-  nsAutoTArray<nsIFrame*,100>    mFramesMarkedForDisplay;
+  nsAutoTArray<nsIFrame*,400>    mFramesMarkedForDisplay;
   nsAutoTArray<ThemeGeometry,2>  mThemeGeometries;
   nsDisplayTableItem*            mCurrentTableItem;
   DisplayListClipState           mClipState;