diff --git a/windows-rdp/main.test.ts b/windows-rdp/main.test.ts
index 4e34285..64738e0 100644
--- a/windows-rdp/main.test.ts
+++ b/windows-rdp/main.test.ts
@@ -1,5 +1,7 @@
 import { describe, expect, it, test } from "bun:test";
 import {
+  JsonValue,
+  TerraformState,
   executeScriptInContainer,
   runTerraformApply,
   runTerraformInit,
@@ -13,6 +15,11 @@ type TestVariables = Readonly<{
   admin_password?: string;
 }>;
 
+/**
+ * @todo It would be nice if we had a way to verify that the Devolutions root
+ * HTML file is modified to include the import for the patched Coder script,
+ * but the current test setup doesn't really make that viable
+ */
 describe("Web RDP", async () => {
   await runTerraformInit(import.meta.dir);
   testRequiredVariables<TestVariables>(import.meta.dir, {
@@ -29,21 +36,38 @@ describe("Web RDP", async () => {
     throw new Error("Not implemented yet");
   });
 
-  /**
-   * @todo Verify that the HTML file has been modified, and that the JS file is
-   * also part of the file system
-   */
-  it("Patches the Devolutions Angular app's .html file to include an import for the custom JS file", async () => {
-    const state = await runTerraformApply<TestVariables>(import.meta.dir, {
-      agent_id: "foo",
-      resource_id: "bar",
-    });
+  it("Injects Terraform's username and password into the JS patch file", async () => {
+    const findInstancesScript = (state: TerraformState): string | null => {
+      let instancesScript: string | null = null;
+      for (const resource of state.resources) {
+        if (resource.type !== "coder_script") {
+          continue;
+        }
 
-    throw new Error("Not implemented yet");
-  });
+        for (const instance of resource.instances) {
+          if (instance.attributes.display_name === "windows-rdp") {
+            instancesScript = instance.attributes.script;
+          }
+        }
+      }
 
-  it("Injects Terraform's username and password into the JS patch file", async () => {
-    throw new Error("Not implemented yet");
+      return instancesScript;
+    };
+
+    /**
+     * Using a regex as a quick-and-dirty way to get at the username and
+     * password values.
+     *
+     * Tried going through the trouble of extracting out the form entries
+     * variable from the main output, converting it from Prettier/JS-based JSON
+     * text to universal JSON text, and exposing it as a parsed JSON value. That
+     * got to be too much, though.
+     *
+     * Written and tested via Regex101
+     * @see {@link https://regex101.com/r/UMgQpv/2}
+     */
+    const formEntryValuesRe =
+      /^const formFieldEntries = \{$.*?^\s+username: \{$.*?^\s*?querySelector.*?,$.*?^\s*value: "(?<username>.+?)",$.*?password: \{$.*?^\s+querySelector: .*?,$.*?^\s*value: "(?<password>.+?)",$.*?^};$/ms;
 
     // Test that things work with the default username/password
     const defaultState = await runTerraformApply<TestVariables>(
@@ -54,19 +78,35 @@ describe("Web RDP", async () => {
       },
     );
 
-    const output = await executeScriptInContainer(defaultState, "alpine");
+    const defaultInstancesScript = findInstancesScript(defaultState);
+    expect(defaultInstancesScript).toBeString();
+
+    const { username: defaultUsername, password: defaultPassword } =
+      formEntryValuesRe.exec(defaultInstancesScript)?.groups ?? {};
+
+    expect(defaultUsername).toBe("Administrator");
+    expect(defaultPassword).toBe("coderRDP!");
 
     // Test that custom usernames/passwords are also forwarded correctly
-    const customUsername = "crouton";
-    const customPassword = "VeryVeryVeryVeryVerySecurePassword97!";
+    const userDefinedUsername = "crouton";
+    const userDefinedPassword = "VeryVeryVeryVeryVerySecurePassword97!";
     const customizedState = await runTerraformApply<TestVariables>(
       import.meta.dir,
       {
         agent_id: "foo",
         resource_id: "bar",
-        admin_username: customUsername,
-        admin_password: customPassword,
+        admin_username: userDefinedUsername,
+        admin_password: userDefinedPassword,
       },
     );
+
+    const customInstancesScript = findInstancesScript(customizedState);
+    expect(customInstancesScript).toBeString();
+
+    const { username: customUsername, password: customPassword } =
+      formEntryValuesRe.exec(customInstancesScript)?.groups ?? {};
+
+    expect(customUsername).toBe(userDefinedUsername);
+    expect(customPassword).toBe(userDefinedPassword);
   });
 });