diff --git a/reactos/ntoskrnl/include/internal/cm.h b/reactos/ntoskrnl/include/internal/cm.h
index a930f05e9cb..e2ce83caaa6 100644
--- a/reactos/ntoskrnl/include/internal/cm.h
+++ b/reactos/ntoskrnl/include/internal/cm.h
@@ -838,6 +838,12 @@ CmpAddToDelayedClose(
     IN BOOLEAN LockHeldExclusively
 );
 
+VOID
+NTAPI
+CmpArmDelayedCloseTimer(
+    VOID
+);
+
 VOID
 NTAPI
 CmpRemoveFromDelayedClose(IN PCM_KEY_CONTROL_BLOCK Kcb);