diff --git a/layout/generic/nsInlineFrame.h b/layout/generic/nsInlineFrame.h
index aeecf814e43..7160619a3a3 100644
--- a/layout/generic/nsInlineFrame.h
+++ b/layout/generic/nsInlineFrame.h
@@ -128,7 +128,9 @@ class nsFirstLineFrame : public nsInlineFrame {
 public:
   friend nsresult NS_NewFirstLineFrame(nsIFrame** aNewFrame);
 
+#ifdef DEBUG
   NS_IMETHOD GetFrameName(nsString& aResult) const;
+#endif
   NS_IMETHOD GetFrameType(nsIAtom** aType) const;
   NS_IMETHOD Reflow(nsIPresContext& aPresContext,
                     nsHTMLReflowMetrics& aDesiredSize,
diff --git a/layout/html/base/src/nsInlineFrame.h b/layout/html/base/src/nsInlineFrame.h
index aeecf814e43..7160619a3a3 100644
--- a/layout/html/base/src/nsInlineFrame.h
+++ b/layout/html/base/src/nsInlineFrame.h
@@ -128,7 +128,9 @@ class nsFirstLineFrame : public nsInlineFrame {
 public:
   friend nsresult NS_NewFirstLineFrame(nsIFrame** aNewFrame);
 
+#ifdef DEBUG
   NS_IMETHOD GetFrameName(nsString& aResult) const;
+#endif
   NS_IMETHOD GetFrameType(nsIAtom** aType) const;
   NS_IMETHOD Reflow(nsIPresContext& aPresContext,
                     nsHTMLReflowMetrics& aDesiredSize,