diff --git a/mozilla/layout/base/nsLayoutUtils.cpp b/mozilla/layout/base/nsLayoutUtils.cpp
index 75aabe33b14..0ecde8256f2 100644
--- a/mozilla/layout/base/nsLayoutUtils.cpp
+++ b/mozilla/layout/base/nsLayoutUtils.cpp
@@ -1735,7 +1735,7 @@ IsAutoHeight(const nsStyleCoord &aCoord, nscoord aCBHeight)
 /* static */ nsSize
 nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(
                    nsIRenderingContext* aRenderingContext, nsIFrame* aFrame,
-                   nsIFrame::IntrinsicSize aIntrinsicSize,
+                   const nsIFrame::IntrinsicSize& aIntrinsicSize,
                    nsSize aIntrinsicRatio, nsSize aCBSize,
                    nsSize aMargin, nsSize aBorder, nsSize aPadding)
 {
diff --git a/mozilla/layout/base/nsLayoutUtils.h b/mozilla/layout/base/nsLayoutUtils.h
index fcd1e0a8adc..0653ade82b1 100644
--- a/mozilla/layout/base/nsLayoutUtils.h
+++ b/mozilla/layout/base/nsLayoutUtils.h
@@ -626,7 +626,7 @@ public:
    */
   static nsSize ComputeSizeWithIntrinsicDimensions(
                     nsIRenderingContext* aRenderingContext, nsIFrame* aFrame,
-                    nsIFrame::IntrinsicSize aIntrinsicSize,
+                    const nsIFrame::IntrinsicSize& aIntrinsicSize,
                     nsSize aIntrinsicRatio, nsSize aCBSize,
                     nsSize aMargin, nsSize aBorder, nsSize aPadding);