diff --git a/mozilla/layout/generic/nsLineLayout.cpp b/mozilla/layout/generic/nsLineLayout.cpp
index 17794ea1856..5e6a0ebbc13 100644
--- a/mozilla/layout/generic/nsLineLayout.cpp
+++ b/mozilla/layout/generic/nsLineLayout.cpp
@@ -1799,7 +1799,7 @@ nsLineLayout::ComputeQuirksModeLineHeightData(nsIRenderingContext *aRC,
   {
     nsCOMPtr<nsIAtom> tag;
     content->GetTag(*(getter_AddRefs(tag)));
-    if (nsHTMLAtoms::font==tag)
+    if (nsHTMLAtoms::font==tag.get())
     {
       nsAutoString resultString;
       nsresult result;
diff --git a/mozilla/layout/html/base/src/nsLineLayout.cpp b/mozilla/layout/html/base/src/nsLineLayout.cpp
index 17794ea1856..5e6a0ebbc13 100644
--- a/mozilla/layout/html/base/src/nsLineLayout.cpp
+++ b/mozilla/layout/html/base/src/nsLineLayout.cpp
@@ -1799,7 +1799,7 @@ nsLineLayout::ComputeQuirksModeLineHeightData(nsIRenderingContext *aRC,
   {
     nsCOMPtr<nsIAtom> tag;
     content->GetTag(*(getter_AddRefs(tag)));
-    if (nsHTMLAtoms::font==tag)
+    if (nsHTMLAtoms::font==tag.get())
     {
       nsAutoString resultString;
       nsresult result;