--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -3247,41 +3247,40 @@ nsComputedDOMStyle::DoGetGridAutoRows()
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetGridTemplateColumns()
 {
   const ComputedGridTrackInfo* info = nullptr;
 
   nsGridContainerFrame* gridFrame =
-    nsGridContainerFrame::GetGridFrameWithComputedInfo(
-      mContent->GetPrimaryFrame());
+    nsGridContainerFrame::GetGridFrameWithComputedInfo(mInnerFrame);
 
   if (gridFrame) {
     info = gridFrame->GetComputedTemplateColumns();
   }
 
   return GetGridTemplateColumnsRows(
     StylePosition()->GridTemplateColumns(), info);
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetGridTemplateRows()
 {
   const ComputedGridTrackInfo* info = nullptr;
 
   nsGridContainerFrame* gridFrame =
-    nsGridContainerFrame::GetGridFrameWithComputedInfo(
-      mContent->GetPrimaryFrame());
+    nsGridContainerFrame::GetGridFrameWithComputedInfo(mInnerFrame);
 
   if (gridFrame) {
     info = gridFrame->GetComputedTemplateRows();
   }
 
-  return GetGridTemplateColumnsRows(StylePosition()->GridTemplateRows(), info);
+  return GetGridTemplateColumnsRows(
+    StylePosition()->GridTemplateRows(), info);
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::GetGridLine(const nsStyleGridLine& aGridLine)
 {
   if (aGridLine.IsAuto()) {
     RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
     val->SetIdent(eCSSKeyword_auto);