diff --git a/include/winuser.h b/include/winuser.h
index fa36381035c..5d8a04be9dc 100644
--- a/include/winuser.h
+++ b/include/winuser.h
@@ -1818,6 +1818,7 @@ typedef struct
 #define BSM_NETDRIVER            0x00000002
 #define BSM_INSTALLABLEDRIVERS   0x00000004
 #define BSM_APPLICATIONS         0x00000008
+#define BSM_ALLDESKTOPS          0x00000010
 
 #define BSF_QUERY                0x00000001
 #define BSF_IGNORECURRENTTASK    0x00000002