diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 4a57e76..336cbea 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -262,8 +262,8 @@
 }
 
 static void handle_buffer_resizing( mbedtls_ssl_context *ssl, int downsizing,
-                                    uint32_t in_buf_new_len,
-                                    uint32_t out_buf_new_len )
+                                    size_t in_buf_new_len,
+                                    size_t out_buf_new_len )
 {
     int modified = 0;
     size_t written_in = 0, iv_offset_in = 0, len_offset_in = 0;