diff --git a/widget/src/os2/nsDeviceContextSpecFactoryO.cpp b/widget/src/os2/nsDeviceContextSpecFactoryO.cpp
index f97931efa2e..70c165b6dd1 100644
--- a/widget/src/os2/nsDeviceContextSpecFactoryO.cpp
+++ b/widget/src/os2/nsDeviceContextSpecFactoryO.cpp
@@ -16,6 +16,7 @@
  * Copyright (C) 1999 John Fairhurst. All Rights Reserved.
  *
  * Contributor(s): 
+ *   Pierre Phaneuf <pp@ludusdesign.com>
  *
  */
 
@@ -38,7 +39,7 @@ nsDeviceContextSpecFactoryOS2::nsDeviceContextSpecFactoryOS2()
    NS_INIT_REFCNT();
 }
 
-NS_IMPL_ISUPPORTS(nsDeviceContextSpecFactoryOS2, nsIDeviceContextSpecFactory::GetIID())
+NS_IMPL_ISUPPORTS(nsDeviceContextSpecFactoryOS2, NS_GET_IID(nsIDeviceContextSpecFactory))
 
 NS_IMETHODIMP nsDeviceContextSpecFactoryOS2::Init()
 {
diff --git a/widget/src/os2/nsDeviceContextSpecOS2.cpp b/widget/src/os2/nsDeviceContextSpecOS2.cpp
index 7fdf0acb0f7..584cf10fad0 100644
--- a/widget/src/os2/nsDeviceContextSpecOS2.cpp
+++ b/widget/src/os2/nsDeviceContextSpecOS2.cpp
@@ -16,6 +16,7 @@
  * Copyright (C) 1999 John Fairhurst. All Rights Reserved.
  *
  * Contributor(s): 
+ *   Pierre Phaneuf <pp@ludusdesign.com>
  *
  */
 
@@ -36,7 +37,7 @@ nsDeviceContextSpecOS2::~nsDeviceContextSpecOS2()
      PrnClosePrinter( mQueue);
 }
 
-NS_IMPL_ISUPPORTS(nsDeviceContextSpecOS2, nsIDeviceContextSpec::GetIID())
+NS_IMPL_ISUPPORTS(nsDeviceContextSpecOS2, NS_GET_IID(nsIDeviceContextSpec))
 
 nsresult nsDeviceContextSpecOS2::Init( PRTQUEUE *pq)
 {