diff --git a/riscv_config/constants.py b/riscv_config/constants.py
index ab410aa..0716dc8 100644
--- a/riscv_config/constants.py
+++ b/riscv_config/constants.py
@@ -33,7 +33,7 @@
         "Zpn", "Zpsf"
 ] + Zve_extensions + Zvl_extensions
 
-S_extensions = ['Smrnmi','Svnapot','Svadu', 'Sdext']
+S_extensions = ['Smrnmi','Svnapot','Svadu','Sdext','Smclint','Ssclint','Smclic','Ssclic','Smclicshv','Smcsrind','Sscsrind']
 
 sub_extensions = Z_extensions + S_extensions