diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 14a3c7e..e136c35 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2048,6 +2048,32 @@
                                           unsigned char **buf,
                                           size_t *buf_len);
 
+/**
+ * \brief Detect if a list of extensions contains a supported_versions
+ *        extension or not.
+ *
+ * \param[in] ssl  SSL context
+ * \param[in] buf  Address of the first byte of the extensions vector.
+ * \param[in] end  End of the buffer containing the list of extensions.
+ * \param[out] extension_data  If the extension is present, address of its first
+ *                             byte of data, NULL otherwise.
+ * \param[out] extension_data_end  If the extension is present, address of the
+ *                                 first byte immediately following the extension
+ *                                 data, NULL otherwise.
+ * \return 0  if the list of extensions does not contain a supported_versions
+ *            extension.
+ * \return 1  if the list of extensions contains a supported_versions
+ *            extension.
+ * \return    A negative value if an error occurred while parsing the
+ *            extensions.
+ */
+MBEDTLS_CHECK_RETURN_CRITICAL
+int mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts(
+    mbedtls_ssl_context *ssl,
+    const unsigned char *buf, const unsigned char *end,
+    const unsigned char **extension_data,
+    const unsigned char **extension_data_end);
+
 /*
  * Handler of TLS 1.3 server certificate message
  */