diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index cc79361c2825..6e444414dad2 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -1619,42 +1619,6 @@ already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetGridTemplateRows() {
   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);
-    return val.forget();
-  }
-
-  RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(false);
-
-  if (aGridLine.mHasSpan) {
-    RefPtr<nsROCSSPrimitiveValue> span = new nsROCSSPrimitiveValue;
-    span->SetIdent(eCSSKeyword_span);
-    valueList->AppendCSSValue(span.forget());
-  }
-
-  if (aGridLine.mInteger != 0) {
-    RefPtr<nsROCSSPrimitiveValue> integer = new nsROCSSPrimitiveValue;
-    integer->SetNumber(aGridLine.mInteger);
-    valueList->AppendCSSValue(integer.forget());
-  }
-
-  if (aGridLine.mLineName != nsGkAtoms::_empty) {
-    RefPtr<nsROCSSPrimitiveValue> lineName = new nsROCSSPrimitiveValue;
-    nsString escapedLineName;
-    nsStyleUtil::AppendEscapedCSSIdent(
-        nsDependentAtomString(aGridLine.mLineName), escapedLineName);
-    lineName->SetString(escapedLineName);
-    valueList->AppendCSSValue(lineName.forget());
-  }
-
-  NS_ASSERTION(valueList->Length() > 0,
-               "Should have appended at least one value");
-  return valueList.forget();
-}
-
 already_AddRefed<CSSValue> nsComputedDOMStyle::DoGetPaddingTop() {
   return GetPaddingWidthFor(eSideTop);
 }
diff --git a/layout/style/nsComputedDOMStyle.h b/layout/style/nsComputedDOMStyle.h
index 05ec2072e6fb..036a5d6a6552 100644
--- a/layout/style/nsComputedDOMStyle.h
+++ b/layout/style/nsComputedDOMStyle.h
@@ -206,7 +206,6 @@ class nsComputedDOMStyle final : public nsDOMCSSDeclaration,
   already_AddRefed<CSSValue> GetGridTemplateColumnsRows(
       const nsStyleGridTemplate& aTrackList,
       const mozilla::ComputedGridTrackInfo* aTrackInfo);
-  already_AddRefed<CSSValue> GetGridLine(const nsStyleGridLine& aGridLine);
 
   bool GetLineHeightCoord(nscoord& aCoord);