diff --git a/vendor/netsurf/wrapper/wrapper.c b/vendor/netsurf/wrapper/wrapper.c
index 0a9448b7..e9704780 100644
--- a/vendor/netsurf/wrapper/wrapper.c
+++ b/vendor/netsurf/wrapper/wrapper.c
@@ -10,7 +10,7 @@
  * \param string The HTML string
  * \return  pointer to DOM document, or NULL on error
  */
-dom_document *wr_create_doc_dom_from_string(char *html)
+dom_document *wr_create_doc_dom_from_string(const char *html)
 {
 	dom_hubbub_parser *parser = NULL;
 	dom_hubbub_error error;
diff --git a/vendor/netsurf/wrapper/wrapper.h b/vendor/netsurf/wrapper/wrapper.h
index ba630a70..c65274e4 100644
--- a/vendor/netsurf/wrapper/wrapper.h
+++ b/vendor/netsurf/wrapper/wrapper.h
@@ -3,7 +3,7 @@
 
 #include <dom/dom.h>
 
-dom_document *wr_create_doc_dom_from_string(char *html);
-dom_document *wr_create_doc_dom_from_file(char *filename);
+dom_document *wr_create_doc_dom_from_string(const char *html);
+dom_document *wr_create_doc_dom_from_file(const char *filename);
 
 #endif	/* wrapper_dom_h_ */