diff --git a/dom/base/RangeUtils.h b/dom/base/RangeUtils.h
index e1fa3ef9394e..98ffc6561444 100644
--- a/dom/base/RangeUtils.h
+++ b/dom/base/RangeUtils.h
@@ -40,7 +40,8 @@ class RangeUtils final {
     // If aNode isn't in the child nodes of its parent node, we hit this case.
     // This may occur when we're called by a mutation observer while aNode is
     // removed from the parent node.
-    if (NS_WARN_IF(afterNode.Offset() == 0)) {
+    if (NS_WARN_IF(
+            !afterNode.Offset(RawRangeBoundary::OffsetFilter::kValidOffsets))) {
       return RawRangeBoundary();
     }
     return afterNode;
diff --git a/dom/base/Selection.cpp b/dom/base/Selection.cpp
index efb76176fa22..7809b1d5b153 100644
--- a/dom/base/Selection.cpp
+++ b/dom/base/Selection.cpp
@@ -2123,7 +2123,9 @@ void Selection::Collapse(const RawRangeBoundary& aPoint, ErrorResult& aRv) {
       aPoint.Container()->IsContent()) {
     int32_t frameOffset;
     nsTextFrame* f = do_QueryFrame(nsCaret::GetFrameAndOffset(
-        this, aPoint.Container(), aPoint.Offset(), &frameOffset));
+        this, aPoint.Container(),
+        *aPoint.Offset(RawRangeBoundary::OffsetFilter::kValidOffsets),
+        &frameOffset));
     if (f && f->IsAtEndOfLine() && f->HasSignificantTerminalNewline()) {
       // RawRangeBounary::Offset() causes computing offset if it's not been
       // done yet.  However, it's called only when the container is a text
@@ -2131,7 +2133,9 @@ void Selection::Collapse(const RawRangeBoundary& aPoint, ErrorResult& aRv) {
       // any children.  So, this doesn't cause computing offset with expensive
       // method, nsINode::ComputeIndexOf().
       if ((aPoint.Container()->AsContent() == f->GetContent() &&
-           f->GetContentEnd() == static_cast<int32_t>(aPoint.Offset())) ||
+           f->GetContentEnd() ==
+               static_cast<int32_t>(*aPoint.Offset(
+                   RawRangeBoundary::OffsetFilter::kValidOffsets))) ||
           (aPoint.Container() == f->GetContent()->GetParentNode() &&
            f->GetContent() == aPoint.GetPreviousSiblingOfChildAtOffset())) {
         frameSelection->SetHint(CARET_ASSOCIATE_AFTER);
diff --git a/dom/base/Selection.h b/dom/base/Selection.h
index 43ff763a7107..7e977d5d1c47 100644
--- a/dom/base/Selection.h
+++ b/dom/base/Selection.h
@@ -231,7 +231,9 @@ class Selection final : public nsSupportsWeakReference,
   }
   uint32_t AnchorOffset() const {
     const RangeBoundary& anchor = AnchorRef();
-    return anchor.IsSet() ? anchor.Offset() : 0;
+    const Maybe<uint32_t> offset =
+        anchor.Offset(RangeBoundary::OffsetFilter::kValidOffsets);
+    return offset ? *offset : 0;
   }
   nsINode* GetFocusNode() const {
     const RangeBoundary& focus = FocusRef();
@@ -239,7 +241,9 @@ class Selection final : public nsSupportsWeakReference,
   }
   uint32_t FocusOffset() const {
     const RangeBoundary& focus = FocusRef();
-    return focus.IsSet() ? focus.Offset() : 0;
+    const Maybe<uint32_t> offset =
+        focus.Offset(RangeBoundary::OffsetFilter::kValidOffsets);
+    return offset ? *offset : 0;
   }
 
   nsIContent* GetChildAtAnchorOffset() {