diff --git a/riscv_config/constants.py b/riscv_config/constants.py
index b9222c6..a48f245 100644
--- a/riscv_config/constants.py
+++ b/riscv_config/constants.py
@@ -32,7 +32,7 @@
         "Zpn", "Zpsf"
 ] + Zve_extensions + Zvl_extensions
 
-S_extensions = ['Smrnmi','Svnapot','Svadu']
+S_extensions = ['Smrnmi','Svnapot','Svadu','Smcsrind','Sscsrind','Smclint','Ssclint','Smclic','Ssclic','Smclicshv']
 
 sub_extensions = Z_extensions + S_extensions