diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 651a17b..8d8af2b 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -631,8 +631,6 @@
     int authmode = MBEDTLS_SSL_VERIFY_REQUIRED;
     mbedtls_x509_crt *ca_chain;
     mbedtls_x509_crl *ca_crl;
-    const char *ext_oid;
-    size_t ext_len;
     uint32_t verify_result = 0;
 
     /* If SNI was used, overwrite authentication mode
@@ -714,34 +712,15 @@
     /*
      * Secondary checks: always done, but change 'ret' only if it was 0
      */
-    /* keyUsage */
-    if ((mbedtls_x509_crt_check_key_usage(
-             ssl->session_negotiate->peer_cert,
-             MBEDTLS_X509_KU_DIGITAL_SIGNATURE) != 0)) {
+    if (mbedtls_ssl_check_cert_usage(ssl->session_negotiate->peer_cert,
+                                     NULL,
+                                     ssl->conf->endpoint,
+                                     MBEDTLS_SSL_VERSION_TLS1_3,
+                                     &verify_result) != 0) {
         MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate (usage extensions)"));
         if (ret == 0) {
             ret = MBEDTLS_ERR_SSL_BAD_CERTIFICATE;
         }
-        verify_result |= MBEDTLS_X509_BADCERT_KEY_USAGE;
-    }
-
-    /* extKeyUsage */
-    if (ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT) {
-        ext_oid = MBEDTLS_OID_SERVER_AUTH;
-        ext_len = MBEDTLS_OID_SIZE(MBEDTLS_OID_SERVER_AUTH);
-    } else {
-        ext_oid = MBEDTLS_OID_CLIENT_AUTH;
-        ext_len = MBEDTLS_OID_SIZE(MBEDTLS_OID_CLIENT_AUTH);
-    }
-
-    if ((mbedtls_x509_crt_check_extended_key_usage(
-             ssl->session_negotiate->peer_cert,
-             ext_oid, ext_len) != 0)) {
-        MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate (usage extensions)"));
-        if (ret == 0) {
-            ret = MBEDTLS_ERR_SSL_BAD_CERTIFICATE;
-        }
-        verify_result |= MBEDTLS_X509_BADCERT_EXT_KEY_USAGE;
     }
 
     /* mbedtls_x509_crt_verify_with_profile is supposed to report a