  We present a new propagation rule for CSS codes. Starting with a CSS code
$[\![n,k,d]\!]_q$, we construct a CSS code with parameters
$[\![n-2,k,d-1]\!]_q$. In general, one would only obtain a code with parameters
$[\![n-2,k,d-2]\!]_q$. The construction applies to asymmetric quantum codes
from the CSS construction as well.
