diff --git a/docshell/base/nsDocShell.h b/docshell/base/nsDocShell.h
index d3608d86a5dc..58487d4aa2b1 100644
--- a/docshell/base/nsDocShell.h
+++ b/docshell/base/nsDocShell.h
@@ -274,7 +274,6 @@ protected:
                                 nsIDocShell **aResult);
 
     PRBool IsFrame();
-    PRBool IsIFrame();
 
     //
     // Helper method that is called when a new document (including any