1 files changed, 1 insertions, 1 deletions

diff --git a/tools/virtio/linux/kernel.h b/tools/virtio/linux/kernel.h
index 395521a7a8d8..fca8381bbe04 100644
--- a/tools/virtio/linux/kernel.h
+++ b/tools/virtio/linux/kernel.h
@@ -118,7 +118,7 @@ static inline void free_page(unsigned long addr)
 #define dev_err(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 #define dev_warn(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 
-#define WARN_ON_ONCE(cond) ((cond) && fprintf (stderr, "WARNING\n"))
+#define WARN_ON_ONCE(cond) ((cond) ? fprintf (stderr, "WARNING\n") : 0)
 
 #define min(x, y) ({                            \
         typeof(x) _min1 = (x);                  \