diff --git a/dom/base/Selection.cpp b/dom/base/Selection.cpp
index b080f98ebbc..0ad66b0882b 100644
--- a/dom/base/Selection.cpp
+++ b/dom/base/Selection.cpp
@@ -331,6 +331,13 @@ const nsTHashSet<const nsINode*>& SelectionNodeCache::MaybeCollect(
     nsTHashSet<const nsINode*> fullySelectedNodes;
     for (size_t rangeIndex = 0; rangeIndex < sel->RangeCount(); ++rangeIndex) {
       AbstractRange* range = sel->GetAbstractRangeAt(rangeIndex);
+      MOZ_ASSERT(range);
+      if (range->Collapsed()) {
+        continue;
+      }
+      if (range->IsStaticRange() && !range->AsStaticRange()->IsValid()) {
+        continue;
+      }
       const RangeBoundary& startRef = range->MayCrossShadowBoundaryStartRef();
       const RangeBoundary& endRef = range->MayCrossShadowBoundaryEndRef();