diff --git a/src/crypto/tls_openssl_ocsp.c b/src/crypto/tls_openssl_ocsp.c
index 4e1c6b94b..8b37b34e7 100644
--- a/src/crypto/tls_openssl_ocsp.c
+++ b/src/crypto/tls_openssl_ocsp.c
@@ -433,7 +433,8 @@ static int issuer_match(X509 *cert, X509 *issuer, CertID *certid)
 	}
 
 	ikey = X509_get0_pubkey_bitstr(issuer);
-	if (!EVP_Digest(ikey->data, ikey->length, md, &len, dgst, NULL) ||
+	if (!ikey ||
+	    !EVP_Digest(ikey->data, ikey->length, md, &len, dgst, NULL) ||
 	    !ASN1_OCTET_STRING_set(hash, md, len)) {
 		ASN1_OCTET_STRING_free(hash);
 		return -1;