diff --git a/src/libcharon/sa/ikev2/keymat_v2.c b/src/libcharon/sa/ikev2/keymat_v2.c
index 49b1f77a5..f8b23b66e 100644
--- a/src/libcharon/sa/ikev2/keymat_v2.c
+++ b/src/libcharon/sa/ikev2/keymat_v2.c
@@ -303,8 +303,8 @@ METHOD(keymat_v2_t, derive_ike_keys, bool,
 	chunk_t nonce_i, chunk_t nonce_r, ike_sa_id_t *id,
 	pseudo_random_function_t rekey_function, chunk_t rekey_skd)
 {
-	chunk_t skeyseed, key, secret, full_nonce, fixed_nonce, prf_plus_seed;
-	chunk_t spi_i, spi_r;
+	chunk_t skeyseed = chunk_empty, key, secret, full_nonce, fixed_nonce;
+	chunk_t prf_plus_seed, spi_i, spi_r;
 	prf_plus_t *prf_plus = NULL;
 	uint16_t alg, key_size, int_alg;
 	prf_t *rekey_prf = NULL;