diff --git a/reactos/include/reactos/undocuser.h b/reactos/include/reactos/undocuser.h
index d00aa24a02b..4332bd2c385 100644
--- a/reactos/include/reactos/undocuser.h
+++ b/reactos/include/reactos/undocuser.h
@@ -57,6 +57,7 @@
 
 /* Caret timer ID */
 #define IDCARETTIMER (0xffff)
+#define ID_TME_TIMER (0xFFFA)
 
 /* SetWindowPos undocumented flags */
 #define SWP_NOCLIENTSIZE 0x0800