diff --git a/layout/base/AccessibleCaretManager.cpp b/layout/base/AccessibleCaretManager.cpp
index 48aabc8986a9..568e0d46e3c3 100644
--- a/layout/base/AccessibleCaretManager.cpp
+++ b/layout/base/AccessibleCaretManager.cpp
@@ -1291,8 +1291,8 @@ nsresult AccessibleCaretManager::DragCaretInternal(const nsPoint& aPoint) {
   return NS_OK;
 }
 
-nsRect AccessibleCaretManager::GetAllChildFrameRectsUnion(
-    nsIFrame* aFrame) const {
+// static
+nsRect AccessibleCaretManager::GetAllChildFrameRectsUnion(nsIFrame* aFrame) {
   nsRect unionRect;
 
   // Drill through scroll frames, we don't want to include scrollbar child
@@ -1342,7 +1342,8 @@ nsPoint AccessibleCaretManager::AdjustDragBoundary(
   if (editingHost) {
     nsIFrame* editingHostFrame = editingHost->GetPrimaryFrame();
     if (editingHostFrame) {
-      nsRect boundary = GetAllChildFrameRectsUnion(editingHostFrame);
+      nsRect boundary =
+          AccessibleCaretManager::GetAllChildFrameRectsUnion(editingHostFrame);
       nsLayoutUtils::TransformRect(editingHostFrame, mPresShell->GetRootFrame(),
                                    boundary);
 
diff --git a/layout/base/AccessibleCaretManager.h b/layout/base/AccessibleCaretManager.h
index 28e0df657967..049c4a44be63 100644
--- a/layout/base/AccessibleCaretManager.h
+++ b/layout/base/AccessibleCaretManager.h
@@ -256,7 +256,7 @@ class AccessibleCaretManager {
   // Get the union of all the child frame scrollable overflow rects for aFrame,
   // which is used as a helper function to restrict the area where the caret can
   // be dragged. Returns the rect relative to aFrame.
-  nsRect GetAllChildFrameRectsUnion(nsIFrame* aFrame) const;
+  static nsRect GetAllChildFrameRectsUnion(nsIFrame* aFrame);
 
   // Restrict the active caret's dragging position based on
   // sCaretsAllowDraggingAcrossOtherCaret. If the active caret is the first