diff --git a/crypto/evp/p_dsa_asn1.c b/crypto/evp/p_dsa_asn1.c
index 1668365d..4790cf62 100644
--- a/crypto/evp/p_dsa_asn1.c
+++ b/crypto/evp/p_dsa_asn1.c
@@ -325,6 +325,7 @@ static int dsa_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey) {
   dplen = i2d_ASN1_INTEGER(prkey, &dp);
 
   ASN1_INTEGER_free(prkey);
+  prkey = NULL;
 
   if (!PKCS8_pkey_set0(p8, (ASN1_OBJECT *)OBJ_nid2obj(NID_dsa), 0,
                        V_ASN1_SEQUENCE, params, dp, dplen)) {