diff --git a/.vscode/extensions.json b/.vscode/extensions.json
new file mode 100644
index 0000000..09cf720
--- /dev/null
+++ b/.vscode/extensions.json
@@ -0,0 +1,5 @@
+{
+  "recommendations": [
+    "denoland.vscode-deno"
+  ]
+}
diff --git a/ast/desugar.test.ts b/ast/desugar.test.ts
index 5dfb6a1..2bd3a07 100644
--- a/ast/desugar.test.ts
+++ b/ast/desugar.test.ts
@@ -1,4 +1,4 @@
-import { assertEquals } from "testing/asserts.ts";
+import { assertEquals } from "assert/mod.ts";
 import { desugar } from "./desugar.ts";
 import { Kind, PrimitiveType } from "./ast.ts";
 
diff --git a/ast/estimate_type.test.ts b/ast/estimate_type.test.ts
index eddf952..c229a34 100644
--- a/ast/estimate_type.test.ts
+++ b/ast/estimate_type.test.ts
@@ -1,4 +1,4 @@
-import { assertEquals } from "testing/asserts.ts";
+import { assertEquals } from "assert/mod.ts";
 import type { Equal, Expect } from "@type-challenges/utils";
 import { type EstimateType } from "./estimate_type.ts";
 import { Kind } from "./ast.ts";
diff --git a/decorator/decorator.test.ts b/decorator/decorator.test.ts
index 0b5bd91..b70ebf1 100644
--- a/decorator/decorator.test.ts
+++ b/decorator/decorator.test.ts
@@ -1,4 +1,4 @@
-import { assertEquals } from "testing/asserts.ts";
+import { assertEquals } from "assert/mod.ts";
 
 import { Decorator } from "./decorator.ts";
 
diff --git a/decorators.test.ts b/decorators.test.ts
index ca864f2..295840f 100644
--- a/decorators.test.ts
+++ b/decorators.test.ts
@@ -1,4 +1,4 @@
-import { assertEquals, assertThrows } from "testing/asserts.ts";
+import { assertEquals, assertThrows } from "assert/mod.ts";
 import { d } from "./decorators.ts";
 import { decorate, union } from "./ast/utils.ts";
 import { createSanitize } from "./validator/create_sanitize.ts";
diff --git a/deno.json b/deno.json
index 860ca32..d3afae7 100644
--- a/deno.json
+++ b/deno.json
@@ -1,15 +1,15 @@
 {
   "imports": {
-    "dnt/": "https://deno.land/x/dnt@0.33.0/",
-    "testing/": "https://deno.land/std@0.179.0/testing/",
-    "@type-challenges/utils": "https://esm.sh/@type-challenges/utils@0.1.1/index.d.ts"
+    "dnt/": "https://deno.land/x/dnt@0.40.0/",
+    "assert/": "https://deno.land/std@0.220.1/assert/",
+    "@type-challenges/utils": "npm:@type-challenges/utils@0.1.1/index.d.ts"
   },
   "tasks": {
     "test": "deno task test:unit && deno task test:lint && deno task test:format && deno task test:types",
     "test:unit": "deno test -A --unstable",
-    "test:lint": "deno lint",
-    "test:format": "deno fmt --check",
-    "test:types": "find . -name '*.ts' | xargs deno check --unstable",
+    "test:lint": "deno lint --ignore=.npm",
+    "test:format": "deno fmt --check --ignore=.npm",
+    "test:types": "find . -name '*.ts' -not -path './.npm/*' | xargs deno check",
     "build:npm": "deno run -A scripts/build_npm.ts"
   }
 }
diff --git a/scripts/build_npm.ts b/scripts/build_npm.ts
index c28a335..a48ce38 100644
--- a/scripts/build_npm.ts
+++ b/scripts/build_npm.ts
@@ -1,8 +1,11 @@
 import { build, emptyDir } from "dnt/mod.ts";
 
-const cmd = Deno.run({ cmd: ["git", "describe", "--tags"], stdout: "piped" });
-const version = new TextDecoder().decode(await cmd.output()).trim();
-cmd.close();
+const cmd = new Deno.Command(Deno.execPath(), {
+  args: ["git", "describe", "--tags"],
+  stdout: "piped",
+});
+const { stdout } = await cmd.output();
+const version = new TextDecoder().decode(stdout).trim();
 
 await emptyDir("./.npm");
 
@@ -14,7 +17,7 @@ await build({
   },
   test: false,
   compilerOptions: {
-    lib: ["es2021", "dom"],
+    lib: ["ES2021", "DOM"],
   },
   package: {
     name: "safen",
diff --git a/short.test.ts b/short.test.ts
index cc8df8a..8aaee29 100644
--- a/short.test.ts
+++ b/short.test.ts
@@ -1,4 +1,4 @@
-import { assert, assertFalse } from "testing/asserts.ts";
+import { assert, assertFalse } from "assert/mod.ts";
 import { v } from "./short.ts";
 
 Deno.test("short, validation, decorate", () => {
diff --git a/validator/create_sanitize.test.ts b/validator/create_sanitize.test.ts
index f495983..3d50cc4 100644
--- a/validator/create_sanitize.test.ts
+++ b/validator/create_sanitize.test.ts
@@ -1,4 +1,4 @@
-import { assertEquals, assertThrows } from "testing/asserts.ts";
+import { assertEquals, assertThrows } from "assert/mod.ts";
 import { between } from "../decorators/between.ts";
 import { email } from "../decorators/email.ts";
 import { ip } from "../decorators/ip.ts";
diff --git a/validator/create_validate.test.ts b/validator/create_validate.test.ts
index 19cd54c..c378a0e 100644
--- a/validator/create_validate.test.ts
+++ b/validator/create_validate.test.ts
@@ -1,7 +1,7 @@
 import { between } from "../decorators/between.ts";
 import { email } from "../decorators/email.ts";
 import { lengthBetween } from "../decorators/length_between.ts";
-import { assert, assertFalse } from "testing/asserts.ts";
+import { assert, assertFalse } from "assert/mod.ts";
 import { any, array, decorate, optional, or, union } from "../ast/utils.ts";
 import { emptyToNull } from "../decorators/empty_to_null.ts";
 import { ip } from "../decorators/ip.ts";