diff --git a/chrome/common/render_messages.h b/chrome/common/render_messages.h
index 75aadd0..3abb6061 100644
--- a/chrome/common/render_messages.h
+++ b/chrome/common/render_messages.h
@@ -440,6 +440,10 @@
 IPC_MESSAGE_ROUTED1(ChromeViewMsg_NetErrorInfo,
                     int /* DNS probe status */)
 
+// Sets the alternate error page URL (Link Doctor) for the renderer process.
+// Handled by the NetErrorHelper.
+IPC_MESSAGE_ROUTED1(ChromeViewMsg_SetAltErrorPageURL, GURL)
+
 //-----------------------------------------------------------------------------
 // Misc messages
 // These are messages sent from the renderer to the browser process.