diff --git a/mailnews/imap/src/nsIMAPHostSessionList.cpp b/mailnews/imap/src/nsIMAPHostSessionList.cpp
index 50f83ba76f3b..7fd64ce80dc2 100644
--- a/mailnews/imap/src/nsIMAPHostSessionList.cpp
+++ b/mailnews/imap/src/nsIMAPHostSessionList.cpp
@@ -20,11 +20,6 @@
 #include "nsIMAPHostSessionList.h"
 #include "nsIMAPBodyShell.h"
 #include "nsIMAPNamespace.h"
-
-#ifdef XP_PC
-#include <windows.h>    // for InterlockedIncrement
-#endif
-
 #include "nsISupportsUtils.h"
 
 nsIMAPHostInfo::nsIMAPHostInfo(const char *hostName, const char *userName)
diff --git a/mailnews/imap/src/nsImapProxyEvent.cpp b/mailnews/imap/src/nsImapProxyEvent.cpp
index 3dd6a4163bc7..ea2ccee0dde7 100644
--- a/mailnews/imap/src/nsImapProxyEvent.cpp
+++ b/mailnews/imap/src/nsImapProxyEvent.cpp
@@ -30,10 +30,6 @@
 #include "nsIMAPNamespace.h"
 #include "nsCOMPtr.h"
 
-#if defined(XP_WIN)
-#include <windows.h>						// for InterlockedIncrement
-#endif
-
 nsImapEvent::nsImapEvent()
 {
     m_notifyCompletion = PR_FALSE;