diff --git a/cmd/pkgserver/ui/static/run_tests.ts b/cmd/pkgserver/ui/static/run_tests.ts
index 1b8bff83..1bfb1e9c 100644
--- a/cmd/pkgserver/ui/static/run_tests.ts
+++ b/cmd/pkgserver/ui/static/run_tests.ts
@@ -1,7 +1,46 @@
 #!/usr/bin/env node
+
 // Many editors have terminal emulators built in, so running tests with NodeJS
 // provides faster iteration, especially for those acclimated to test-driven
 // development.
+
 import "./all_tests.js";
 import { StreamReporter, TESTS } from "./test.js";
-TESTS.run(new StreamReporter({ writeln: console.log }));
+
+// TypeScript doesn't like process and Deno as their type definitions aren't
+// installed, but doesn't seem to complain if they're accessed through
+// globalThis.
+const process: any = globalThis.process;
+const Deno: any = globalThis.Deno;
+
+function getArgs(): string[] {
+    if (process) {
+        const [runtime, program, ...args] = process.argv;
+        return args;
+    }
+    if (Deno) return Deno.args;
+    return [];
+}
+
+function exit(code?: number): never {
+    if (Deno) Deno.exit(code);
+    if (process) process.exit(code);
+    throw `exited with code ${code ?? 0}`;
+}
+
+const args = getArgs();
+let verbose = false;
+if (args.length > 1) {
+    console.error("Too many arguments");
+    exit(1);
+}
+if (args.length === 1) {
+    if (args[0] === "-v" || args[0] === "--verbose" || args[0] === "-verbose") {
+        verbose = true;
+    } else if (args[0] !== "--") {
+        console.error(`Unknown argument '${args[0]}'`);
+        exit(1);
+    }
+}
+
+TESTS.run(new StreamReporter({ writeln: console.log }, verbose));