diff --git a/src/libstrongswan/crypto/crypters/crypter.c b/src/libstrongswan/crypto/crypters/crypter.c
index 1d156d101..806e973b7 100644
--- a/src/libstrongswan/crypto/crypters/crypter.c
+++ b/src/libstrongswan/crypto/crypters/crypter.c
@@ -16,9 +16,7 @@
 
 #include "crypter.h"
 
-ENUM_BEGIN(encryption_algorithm_names, ENCR_UNDEFINED, ENCR_UNDEFINED,
-	"UNDEFINED");
-ENUM_NEXT(encryption_algorithm_names, ENCR_DES_IV64, ENCR_DES_IV32, ENCR_UNDEFINED,
+ENUM_BEGIN(encryption_algorithm_names, ENCR_DES_IV64, ENCR_DES_IV32,
 	"DES_IV64",
 	"DES",
 	"3DES",
@@ -46,7 +44,10 @@ ENUM_NEXT(encryption_algorithm_names, ENCR_CAMELLIA_CBC, ENCR_CAMELLIA_CCM_ICV16
 	"CAMELLIA_CCM_ICV8",
 	"CAMELLIA_CCM_ICV12",
 	"CAMELLIA_CCM_ICV16");
-ENUM_NEXT(encryption_algorithm_names, ENCR_DES_ECB, ENCR_DES_ECB, ENCR_CAMELLIA_CCM_ICV16,
-	"DES_ECB");
-ENUM_END(encryption_algorithm_names, ENCR_DES_ECB);
+ENUM_NEXT(encryption_algorithm_names, ENCR_UNDEFINED, ENCR_TWOFISH, ENCR_CAMELLIA_CCM_ICV16,
+	"UNDEFINED",
+	"DES_ECB",
+	"SERPENT",
+	"TWOFISH");
+ENUM_END(encryption_algorithm_names, ENCR_TWOFISH);
 
diff --git a/src/libstrongswan/crypto/crypters/crypter.h b/src/libstrongswan/crypto/crypters/crypter.h
index 110c35f89..f01ea5bd7 100644
--- a/src/libstrongswan/crypto/crypters/crypter.h
+++ b/src/libstrongswan/crypto/crypters/crypter.h
@@ -31,7 +31,6 @@ typedef struct crypter_t crypter_t;
  * Encryption algorithm, as in IKEv2 RFC 3.3.2.
  */
 enum encryption_algorithm_t {
-	ENCR_UNDEFINED =        1024,
 	ENCR_DES_IV64 =            1,
 	ENCR_DES =                 2,
 	ENCR_3DES =                3,
@@ -56,7 +55,10 @@ enum encryption_algorithm_t {
 	ENCR_CAMELLIA_CCM_ICV8 =  25,
 	ENCR_CAMELLIA_CCM_ICV12 = 26,
 	ENCR_CAMELLIA_CCM_ICV16 = 27,
-    ENCR_DES_ECB =          1025
+	ENCR_UNDEFINED =        1024,
+    ENCR_DES_ECB =          1025,
+	ENCR_SERPENT =          1026,
+    ENCR_TWOFISH =          1027
 };
 
 /**