diff --git a/mozilla/gfx/idl/gfxIImageFrame.idl b/mozilla/gfx/idl/gfxIImageFrame.idl
index ecaa1218fde..ff36b763596 100644
--- a/mozilla/gfx/idl/gfxIImageFrame.idl
+++ b/mozilla/gfx/idl/gfxIImageFrame.idl
@@ -30,7 +30,6 @@
 #include "nsRect.h"
 %}
 
-interface gfxIImageFrame;
 native nsRectRef(nsRect &);
 
 /**
diff --git a/mozilla/gfx/public/gfxIImageFrame.idl b/mozilla/gfx/public/gfxIImageFrame.idl
index ecaa1218fde..ff36b763596 100644
--- a/mozilla/gfx/public/gfxIImageFrame.idl
+++ b/mozilla/gfx/public/gfxIImageFrame.idl
@@ -30,7 +30,6 @@
 #include "nsRect.h"
 %}
 
-interface gfxIImageFrame;
 native nsRectRef(nsRect &);
 
 /**
diff --git a/mozilla/gfx2/public/gfxIImageFrame.idl b/mozilla/gfx2/public/gfxIImageFrame.idl
index ecaa1218fde..ff36b763596 100644
--- a/mozilla/gfx2/public/gfxIImageFrame.idl
+++ b/mozilla/gfx2/public/gfxIImageFrame.idl
@@ -30,7 +30,6 @@
 #include "nsRect.h"
 %}
 
-interface gfxIImageFrame;
 native nsRectRef(nsRect &);
 
 /**