diff --git a/config/subclades_for_titer_plots_h1n1pdm.txt b/config/subclades_for_titer_plots_h1n1pdm.txt
index ca011024..938d0608 100644
--- a/config/subclades_for_titer_plots_h1n1pdm.txt
+++ b/config/subclades_for_titer_plots_h1n1pdm.txt
@@ -2,5 +2,6 @@ C.1
 C.1.1
 C.1.1.1
 C.1.2
+C.1.3
 C.1.5
 C.1.6