--- a/toolkit/components/extensions/schemas/web_request.json
+++ b/toolkit/components/extensions/schemas/web_request.json
@@ -47,16 +47,17 @@
           "beacon",
           "xml_dtd",
           "font",
           "media",
           "websocket",
           "csp_report",
           "imageset",
           "web_manifest",
+          "speculative",
           "other"
         ]
       },
       {
         "id": "OnBeforeRequestOptions",
         "type": "string",
         "enum": ["blocking", "requestBody"]
       },

--- a/toolkit/components/extensions/test/xpcshell/test_ext_proxy_speculative.js
+++ b/toolkit/components/extensions/test/xpcshell/test_ext_proxy_speculative.js
@@ -6,17 +6,17 @@ const proxy = createHttpServer();
 
 add_task(async function test_speculative_connect() {
   function background() {
     // Handle the proxy request.
     browser.proxy.onRequest.addListener(details => {
       browser.test.log(`onRequest ${JSON.stringify(details)}`);
       browser.test.assertEq(details.type, "speculative", "Should have seen a speculative proxy request.");
       return [{type: "direct"}];
-    }, {urls: ["<all_urls>"]}, ["requestHeaders"]);
+    }, {urls: ["<all_urls>"], types: ["speculative"]});
   }
 
   let handlingExt = ExtensionTestUtils.loadExtension({
     manifest: {
       permissions: [
         "proxy",
         "<all_urls>",
       ],