diff --git a/fs/timerfd.c b/fs/timerfd.c
index 75d44ef..c502c60 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -184,6 +184,10 @@
 	int ufd;
 	struct timerfd_ctx *ctx;
 
+	/* Check the TFD_* constants for consistency.  */
+	BUILD_BUG_ON(TFD_CLOEXEC != O_CLOEXEC);
+	BUILD_BUG_ON(TFD_NONBLOCK != O_NONBLOCK);
+
 	if (flags & ~(TFD_CLOEXEC | TFD_NONBLOCK))
 		return -EINVAL;
 	if (clockid != CLOCK_MONOTONIC &&