diff --git a/src/cipher_analytical_machine/cli/options.clj b/src/cipher_analytical_machine/cli/options.clj
index fc9394e..dd93152 100644
--- a/src/cipher_analytical_machine/cli/options.clj
+++ b/src/cipher_analytical_machine/cli/options.clj
@@ -22,7 +22,7 @@
     (option-values-as-list option values)))
 
 (def cipher-options
-  #{"Caesar" "Simple substitution and Caesar"})
+  #{"Caesar" "Simple substitution and Caesar" "Gamma"})
 
 (def default-cipher "Caesar")