diff --git a/mcxtrace-comps/optics/Capillary.comp b/mcxtrace-comps/optics/Capillary.comp
index d8d853267..16d4d2989 100644
--- a/mcxtrace-comps/optics/Capillary.comp
+++ b/mcxtrace-comps/optics/Capillary.comp
@@ -24,7 +24,7 @@
 * $\theta' = \theta + \delta \theta \in [-min(theta,\Delta\theta,\Delta\theta]$
 * </div>
 * This ensures that reflected rays will never be scattered into the capillary.
-* \Delta\theta is the value specified by the parameter waviness.
+* <span class="latex">$\Delta\theta$</span> is the value specified by the parameter waviness.
 *
 * Example: Capillary(
 *       radius=1e-4,length=0.1, R0=0, coating="Rh.txt")