diff --git a/fs/vfs/fs_fcntl.c b/fs/vfs/fs_fcntl.c
index f796fa5b23..64c244970f 100644
--- a/fs/vfs/fs_fcntl.c
+++ b/fs/vfs/fs_fcntl.c
@@ -151,7 +151,7 @@ static int file_vfcntl(FAR struct file *filep, int cmd, va_list ap)
               filep->f_oflags &= ~(FFCNTL & ~O_NONBLOCK);
               filep->f_oflags |=  oflags;
 
-              if (filep->f_oflags & O_APPEND)
+              if ((filep->f_oflags & O_APPEND) != 0)
                 {
                   file_seek(filep, 0, SEEK_END);
                 }