diff --git a/src/shrpx_config.cc b/src/shrpx_config.cc
index 56d265ca..6a241efa 100644
--- a/src/shrpx_config.cc
+++ b/src/shrpx_config.cc
@@ -1199,6 +1199,7 @@ int read_tls_sct_from_dir(std::vector<uint8_t> &dst, const StringRef &opt,
 }
 } // namespace
 
+#if !LIBRESSL_IN_USE
 namespace {
 // Reads PSK secrets from path, and parses each line.  The result is
 // directly stored into config->tls.psk_secrets.  This function
@@ -1262,7 +1263,9 @@ int parse_psk_secrets(Config *config, const StringRef &path) {
   return 0;
 }
 } // namespace
+#endif // !LIBRESSL_IN_USE
 
+#if !LIBRESSL_IN_USE
 namespace {
 // Reads PSK secrets from path, and parses each line.  The result is
 // directly stored into config->tls.client.psk.  This function returns
@@ -1322,6 +1325,7 @@ int parse_client_psk_secrets(Config *config, const StringRef &path) {
   return 0;
 }
 } // namespace
+#endif // !LIBRESSL_IN_USE
 
 // generated by gennghttpxfun.py
 int option_lookup_token(const char *name, size_t namelen) {
@@ -3284,9 +3288,23 @@ int parse_config(Config *config, int optid, const StringRef &opt,
     return parse_duration(&config->conn.upstream.timeout.idle_read, opt,
                           optarg);
   case SHRPX_OPTID_PSK_SECRETS:
+#if !LIBRESSL_IN_USE
     return parse_psk_secrets(config, optarg);
+#else  // LIBRESSL_IN_USE
+    LOG(WARN)
+        << opt
+        << ": ignored because underlying TLS library does not support PSK";
+    return 0;
+#endif // LIBRESSL_IN_USE
   case SHRPX_OPTID_CLIENT_PSK_SECRETS:
+#if !LIBRESSL_IN_USE
     return parse_client_psk_secrets(config, optarg);
+#else  // LIBRESSL_IN_USE
+    LOG(WARN)
+        << opt
+        << ": ignored because underlying TLS library does not support PSK";
+    return 0;
+#endif // LIBRESSL_IN_USE
   case SHRPX_OPTID_CLIENT_NO_HTTP2_CIPHER_BLACK_LIST:
     config->tls.client.no_http2_cipher_black_list =
         util::strieq_l("yes", optarg);
diff --git a/src/shrpx_ssl.cc b/src/shrpx_ssl.cc
index c5df1204..29cdf781 100644
--- a/src/shrpx_ssl.cc
+++ b/src/shrpx_ssl.cc
@@ -525,6 +525,7 @@ int sct_parse_cb(SSL *ssl, unsigned int ext_type, const unsigned char *in,
 } // namespace
 #endif // !LIBRESSL_IN_USE && OPENSSL_VERSION_NUMBER >= 0x10002000L
 
+#if !LIBRESSL_IN_USE
 namespace {
 unsigned int psk_server_cb(SSL *ssl, const char *identity, unsigned char *psk,
                            unsigned int max_psk_len) {
@@ -548,7 +549,9 @@ unsigned int psk_server_cb(SSL *ssl, const char *identity, unsigned char *psk,
   return static_cast<unsigned int>(secret.size());
 }
 } // namespace
+#endif // !LIBRESSL_IN_USE
 
+#if !LIBRESSL_IN_USE
 namespace {
 unsigned int psk_client_cb(SSL *ssl, const char *hint, char *identity_out,
                            unsigned int max_identity_len, unsigned char *psk,
@@ -581,6 +584,7 @@ unsigned int psk_client_cb(SSL *ssl, const char *hint, char *identity_out,
   return (unsigned int)secret.size();
 }
 } // namespace
+#endif // !LIBRESSL_IN_USE
 
 struct TLSProtocol {
   StringRef name;
@@ -784,7 +788,9 @@ SSL_CTX *create_ssl_context(const char *private_key_file, const char *cert_file,
   }
 #endif // !LIBRESSL_IN_USE && OPENSSL_VERSION_NUMBER >= 0x10002000L
 
+#if !LIBRESSL_IN_USE
   SSL_CTX_set_psk_server_callback(ssl_ctx, psk_server_cb);
+#endif // !LIBRESSL_IN_USE
 
   auto tls_ctx_data = new TLSContextData();
   tls_ctx_data->cert_file = cert_file;
@@ -919,7 +925,9 @@ SSL_CTX *create_ssl_client_context(
 #endif // HAVE_NEVERBLEED
   }
 
+#if !LIBRESSL_IN_USE
   SSL_CTX_set_psk_client_callback(ssl_ctx, psk_client_cb);
+#endif // !LIBRESSL_IN_USE
 
   // NPN selection callback.  This is required to set SSL_CTX because
   // OpenSSL does not offer SSL_set_next_proto_select_cb.