diff --git a/registry/coder/modules/vscode-web/main.test.ts b/registry/coder/modules/vscode-web/main.test.ts
index 860fc176..e415fa7d 100644
--- a/registry/coder/modules/vscode-web/main.test.ts
+++ b/registry/coder/modules/vscode-web/main.test.ts
@@ -38,5 +38,17 @@ describe("vscode-web", async () => {
     expect(t).toThrow("Offline mode does not allow extensions to be installed");
   });
 
+  it("folder and workspace can not be used together", () => {
+    const t = async () => {
+      await runTerraformApply(import.meta.dir, {
+        agent_id: "foo",
+        accept_license: "true",
+        folder: "/home/coder",
+        workspace: "/home/coder/project.code-workspace",
+      });
+    };
+    expect(t).toThrow("Cannot specify both 'folder' and 'workspace'. Please use only one.");
+  });
+
   // More tests depend on shebang refactors
-});
+});
\ No newline at end of file