diff --git a/src/dom/node.zig b/src/dom/node.zig
index 904119e0..3d3ea43c 100644
--- a/src/dom/node.zig
+++ b/src/dom/node.zig
@@ -180,6 +180,11 @@ pub const Node = struct {
         return parser.nodeLookupPrefix(self, namespace);
     }
 
+    pub fn _lookupNamespaceURI(self: *parser.Node, prefix: ?[]const u8) ?[]const u8 {
+        // TODO: other is not an optional parameter, but can be null.
+        return parser.nodeLookupNamespaceURI(self, prefix);
+    }
+
     pub fn _normalize(self: *parser.Node) void {
         return parser.nodeNormalize(self);
     }
diff --git a/src/netsurf.zig b/src/netsurf.zig
index 6bf5ea54..4cf6184b 100644
--- a/src/netsurf.zig
+++ b/src/netsurf.zig
@@ -398,6 +398,15 @@ pub fn nodeLookupPrefix(node: *Node, namespace: ?[]const u8) ?[]const u8 {
     return stringToData(s.?);
 }
 
+pub fn nodeLookupNamespaceURI(node: *Node, prefix: ?[]const u8) ?[]const u8 {
+    var s: ?*String = undefined;
+    _ = nodeVtable(node).dom_node_lookup_namespace.?(node, stringFromData(prefix.?), &s);
+    if (s == null) {
+        return null;
+    }
+    return stringToData(s.?);
+}
+
 pub fn nodeNormalize(node: *Node) void {
     _ = nodeVtable(node).dom_node_normalize.?(node);
 }