diff --git a/src/passes/operators/operators.ml b/src/passes/operators/operators.ml
index e1bfb0417..b19d1724a 100644
--- a/src/passes/operators/operators.ml
+++ b/src/passes/operators/operators.ml
@@ -77,6 +77,7 @@ module Simplify = struct
       ("bitwise_xor" , "XOR") ;
       ("string_concat" , "CONCAT") ;
       ("string_slice" , "SLICE") ;
+      ("crypto_check", "CHECK_SIGNATURE") ;
       ("bytes_concat" , "CONCAT") ;
       ("bytes_slice" , "SLICE") ;
       ("bytes_pack" , "PACK") ;