diff --git a/dlls/ntdll/file.c b/dlls/ntdll/file.c
index bdbf12182a2..cf95cd051d1 100644
--- a/dlls/ntdll/file.c
+++ b/dlls/ntdll/file.c
@@ -1587,6 +1587,7 @@ NTSTATUS WINAPI NtFsControlFile(HANDLE handle, HANDLE event, PIO_APC_ROUTINE apc
         status = RtlImpersonateSelf( SecurityImpersonation );
         break;
 
+    case FSCTL_IS_VOLUME_MOUNTED:
     case FSCTL_LOCK_VOLUME:
     case FSCTL_UNLOCK_VOLUME:
         FIXME("stub! return success - Unsupported fsctl %x (device=%x access=%x func=%x method=%x)\n",