diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index e60b82f..5a72fed 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -532,9 +532,9 @@
     }
 }
 
-static void mbedtls_ssl_add_hs_hdr_to_checksum( mbedtls_ssl_context *ssl,
-                                                unsigned hs_type,
-                                                size_t total_hs_len )
+void mbedtls_ssl_add_hs_hdr_to_checksum( mbedtls_ssl_context *ssl,
+                                         unsigned hs_type,
+                                         size_t total_hs_len )
 {
     unsigned char hs_hdr[4];