diff --git a/src/libcharon/sa/ikev1/keymat_v1.c b/src/libcharon/sa/ikev1/keymat_v1.c
index 1de05b4ec..bcea1f388 100644
--- a/src/libcharon/sa/ikev1/keymat_v1.c
+++ b/src/libcharon/sa/ikev1/keymat_v1.c
@@ -219,7 +219,6 @@ static aead_t *create_aead(proposal_t *proposal, prf_t *prf, chunk_t skeyid_e,
 			 encryption_algorithm_names, alg, key_size);
 		return NULL;
 	}
-	key_size = crypter->get_key_size(crypter);
 	if (!expand_skeyid_e(skeyid_e, crypter->get_key_size(crypter), prf, ka))
 	{
 		return NULL;