diff --git a/crypto/dsa/dsa_ameth.c b/crypto/dsa/dsa_ameth.c
index 73dd158ceea70de76720ad3bd9c4d3e234168022..0002e0810e34531231f063a277ac9ecf3a290990 100644
--- a/crypto/dsa/dsa_ameth.c
+++ b/crypto/dsa/dsa_ameth.c
@@ -321,6 +321,7 @@ static int dsa_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 
     ASN1_STRING_clear_free(prkey);
+    prkey = NULL;
 
     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_dsa), 0,
                          V_ASN1_SEQUENCE, params, dp, dplen))