diff --git a/dictsource/ru_rules b/dictsource/ru_rules
index e4d40834..652ccae6 100644
--- a/dictsource/ru_rules
+++ b/dictsource/ru_rules
@@ -137,6 +137,7 @@
         д (к   t
         д (нь   d;
         д (п   t
+        д (с   t
         д (сY   t;
         д (тY   t;
         д (фY   t