diff --git a/NEWS b/NEWS
index 806659094a9..c31c390cb4a 100644
--- a/NEWS
+++ b/NEWS
@@ -16,6 +16,7 @@ PHP                                                                        NEWS
     (ndossche)
   . Fixed bug GH-20395 (querySelector and querySelectorAll requires elements
     in $selectors to be lowercase). (ndossche)
+  . Fix missing NUL byte check on C14NFile(). (ndossche)
 
 - Opcache:
   . Fixed bug GH-20329 (opcache.file_cache broken with full interned string
diff --git a/ext/dom/node.c b/ext/dom/node.c
index 105f4cb73a0..3ec1db84157 100644
--- a/ext/dom/node.c
+++ b/ext/dom/node.c
@@ -2126,7 +2126,7 @@ static void dom_canonicalization(INTERNAL_FUNCTION_PARAMETERS, int mode) /* {{{
 		}
 	} else {
 		if (zend_parse_parameters(ZEND_NUM_ARGS(),
-			"s|bba!a!", &file, &file_len, &exclusive,
+			"p|bba!a!", &file, &file_len, &exclusive,
 			&with_comments, &xpath_array, &ns_prefixes) == FAILURE) {
 			RETURN_THROWS();
 		}