diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 2ec898b..948c802 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2852,6 +2852,13 @@
                                      const char *hostname);
 #endif
 
+#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_EARLY_DATA) && \
+    defined(MBEDTLS_SSL_ALPN)
+MBEDTLS_CHECK_RETURN_CRITICAL
+int mbedtls_ssl_session_set_alpn(mbedtls_ssl_session *session,
+                                 const char *alpn);
+#endif
+
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3) && defined(MBEDTLS_SSL_SESSION_TICKETS)
 
 #define MBEDTLS_SSL_TLS1_3_MAX_ALLOWED_TICKET_LIFETIME (604800)