--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -4064,9 +4064,6 @@ ngx_ssl_session_ticket_key_callback(ngx_
     ngx_ssl_session_ticket_key_t  *key;
     const EVP_MD                  *digest;
     const EVP_CIPHER              *cipher;
-#if (NGX_DEBUG)
-    u_char                         buf[32];
-#endif
 
     c = ngx_ssl_get_connection(ssl_conn);
     ssl_ctx = c->ssl->session_ctx;
@@ -4088,8 +4085,8 @@ ngx_ssl_session_ticket_key_callback(ngx_
         /* encrypt session ticket */
 
         ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                       "ssl session ticket encrypt, key: \"%*s\" (%s session)",
-                       ngx_hex_dump(buf, key[0].name, 16) - buf, buf,
+                       "ssl session ticket encrypt, key: \"%*xs\" (%s session)",
+                       (size_t) 16, key[0].name,
                        SSL_session_reused(ssl_conn) ? "reused" : "new");
 
         if (key[0].size == 48) {
@@ -4135,17 +4132,16 @@ ngx_ssl_session_ticket_key_callback(ngx_
         }
 
         ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                       "ssl session ticket decrypt, key: \"%*s\" not found",
-                       ngx_hex_dump(buf, name, 16) - buf, buf);
+                       "ssl session ticket decrypt, key: \"%*xs\" not found",
+                       (size_t) 16, name);
 
         return 0;
 
     found:
 
         ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                       "ssl session ticket decrypt, key: \"%*s\"%s",
-                       ngx_hex_dump(buf, key[i].name, 16) - buf, buf,
-                       (i == 0) ? " (default)" : "");
+                       "ssl session ticket decrypt, key: \"%*xs\"%s",
+                       (size_t) 16, key[i].name, (i == 0) ? " (default)" : "");
 
         if (key[i].size == 48) {
             cipher = EVP_aes_128_cbc();