--- a/accessible/base/nsAccessibilityService.cpp
+++ b/accessible/base/nsAccessibilityService.cpp
@@ -1555,19 +1555,19 @@ nsAccessibilityService::CreateAccessible
         newAcc = new HTMLTableCellAccessibleWrap(aContent, document);
       else
         newAcc = new HyperTextAccessibleWrap(aContent, document);
       break;
 
     case eHTMLTableRowType: {
       // Accessible HTML table row may be a child of tbody/tfoot/thead of
       // accessible HTML table or a direct child of accessible of HTML table.
-      Accessible* table = aContext->IsTable() ?
-        aContext :
-        (aContext->Parent()->IsTable() ? aContext->Parent() : nullptr);
+      Accessible* table = aContext->IsTable() ? aContext : nullptr;
+      if (!table && aContext->Parent() && aContext->Parent()->IsTable())
+        table = aContext->Parent();
 
       if (table) {
         nsIContent* parentContent = aContent->GetParent();
         nsIFrame* parentFrame = parentContent->GetPrimaryFrame();
         if (parentFrame->GetType() != nsGkAtoms::tableOuterFrame) {
           parentContent = parentContent->GetParent();
           parentFrame = parentContent->GetPrimaryFrame();
         }