diff --git a/OpenChange/MAPIStoreUserContext.h b/OpenChange/MAPIStoreUserContext.h
index 01b6ef7e8..43ae2e7ed 100644
--- a/OpenChange/MAPIStoreUserContext.h
+++ b/OpenChange/MAPIStoreUserContext.h
@@ -25,6 +25,7 @@
 
 #import <Foundation/NSObject.h>
 
+@class NSMutableDictionary;
 @class NSString;
 
 @class WOContext;