diff --git a/dom/webidl/XPathEvaluator.webidl b/dom/webidl/XPathEvaluator.webidl
index a74909f2ab..9e5cc75745 100644
--- a/dom/webidl/XPathEvaluator.webidl
+++ b/dom/webidl/XPathEvaluator.webidl
@@ -9,11 +9,13 @@ interface XPathEvaluator {
   // Based on nsIDOMXPathEvaluator
   [NewObject, Throws]
   XPathExpression createExpression(DOMString expression,
-                                   XPathNSResolver? resolver);
+                                   optional XPathNSResolver? resolver = null);
   [Pure]
   Node createNSResolver(Node nodeResolver);
   [Throws]
-  XPathResult evaluate(DOMString expression, Node contextNode,
-                       XPathNSResolver? resolver, unsigned short type,
-                       object? result);
+  XPathResult evaluate(DOMString expression,
+                       Node contextNode,
+                       optional XPathNSResolver? resolver = null,
+                       optional unsigned short type = 0 /* XPathResult.ANY_TYPE */,
+                       optional object? result = null);
 };
diff --git a/dom/webidl/XPathExpression.webidl b/dom/webidl/XPathExpression.webidl
index dd5835492e..4606cb9bd9 100644
--- a/dom/webidl/XPathExpression.webidl
+++ b/dom/webidl/XPathExpression.webidl
@@ -6,17 +6,20 @@
 
 interface XPathExpression {
   // The result specifies a specific result object which may be reused and
-  // returned by this method. If this is specified as null or it's not an
+  // returned by this method. If this is omitted, specified as null, or it's not an
   // XPathResult object, a new result object will be constructed and returned.
   [Throws]
-  XPathResult evaluate(Node contextNode, unsigned short type, object? result);
+  XPathResult evaluate(Node contextNode,
+                       optional unsigned short type = 0  /* XPathResult.ANY_TYPE */,
+                       optional object? result = null);
 
   // The result specifies a specific result object which may be reused and
-  // returned by this method. If this is specified as null or it's not an
+  // returned by this method. If this is omitted, specified as null, or it's not an
   // XPathResult object, a new result object will be constructed and returned.
   [Throws, ChromeOnly]
   XPathResult evaluateWithContext(Node contextNode,
                                   unsigned long contextPosition,
                                   unsigned long contextSize,
-                                  unsigned short type, object? result);
+                                  optional unsigned short type = 0  /* XPathResult.ANY_TYPE */,
+                                  optional object? result = null);
 };
diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index 7bbfdca926..f00cb9c687 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -2288,8 +2288,7 @@ Parser<FullParseHandler>::moduleBody(ModuleSharedContext* modulesc)
             if (!str.encodeLatin1(context, name))
                 return null();
 
-            JS_ReportErrorNumberLatin1(context->asJSContext(), GetErrorMessage, nullptr,
-                                       JSMSG_MISSING_EXPORT, str.ptr());
+            error(JSMSG_MISSING_EXPORT, str.ptr());
             return null();
         }