diff --git a/ext/cron/lib.rs b/ext/cron/lib.rs
index 7a3bb68763171b..63dfa4f52c3d42 100644
--- a/ext/cron/lib.rs
+++ b/ext/cron/lib.rs
@@ -32,7 +32,7 @@ deno_core::extension!(deno_cron,
     op_cron_create<C>,
     op_cron_next<C>,
   ],
-  esm = [ "01_cron.ts" ],
+  lazy_loaded_esm = [ "01_cron.ts" ],
   options = {
     cron_handler: C,
   },
diff --git a/ext/ffi/lib.rs b/ext/ffi/lib.rs
index b1fe4399b025bd..e6aa8ad44fbcdd 100644
--- a/ext/ffi/lib.rs
+++ b/ext/ffi/lib.rs
@@ -80,7 +80,7 @@ deno_core::extension!(deno_ffi,
     op_ffi_unsafe_callback_ref,
     op_ffi_get_turbocall_target,
   ],
-  esm = [ "00_ffi.js" ],
+  lazy_loaded_esm = [ "00_ffi.js" ],
   options = {
     deno_rt_native_addon_loader: Option<DenoRtNativeAddonLoaderRc>,
   },
diff --git a/ext/kv/lib.rs b/ext/kv/lib.rs
index 006e4b58e41376..7bc11fb41b13a0 100644
--- a/ext/kv/lib.rs
+++ b/ext/kv/lib.rs
@@ -76,7 +76,7 @@ deno_core::extension!(deno_kv,
     op_kv_watch<DBH>,
     op_kv_watch_next,
   ],
-  esm = [ "01_db.ts" ],
+  lazy_loaded_esm = [ "01_db.ts" ],
   options = {
     handler: DBH,
     config: KvConfig,
diff --git a/ext/os/lib.rs b/ext/os/lib.rs
index 623d98951c6392..6bfaff2ff3ed0a 100644
--- a/ext/os/lib.rs
+++ b/ext/os/lib.rs
@@ -96,7 +96,8 @@ deno_core::extension!(
     ops::signal::op_signal_unbind,
     ops::signal::op_signal_poll,
   ],
-  esm = ["30_os.js", "40_signals.js"],
+  esm = ["30_os.js"],
+  lazy_loaded_esm = ["40_signals.js"],
   options = {
     exit_code: Option<ExitCode>,
   },
diff --git a/runtime/js/90_deno_ns.js b/runtime/js/90_deno_ns.js
index 08b6bef25d72dd..570580fcf7c8bb 100644
--- a/runtime/js/90_deno_ns.js
+++ b/runtime/js/90_deno_ns.js
@@ -11,7 +11,6 @@ import {
 import * as timers from "ext:deno_web/02_timers.js";
 import * as httpClient from "ext:deno_fetch/22_http_client.js";
 import * as console from "ext:deno_web/01_console.js";
-import * as ffi from "ext:deno_ffi/00_ffi.js";
 import * as net from "ext:deno_net/01_net.js";
 import * as tls from "ext:deno_net/02_tls.js";
 import * as serve from "ext:deno_http/00_serve.ts";
@@ -23,12 +22,8 @@ import * as permissions from "ext:runtime/10_permissions.js";
 import * as io from "ext:deno_io/12_io.js";
 import * as fs from "ext:deno_fs/30_fs.js";
 import * as os from "ext:deno_os/30_os.js";
-import * as fsEvents from "ext:runtime/40_fs_events.js";
 import * as process from "ext:deno_process/40_process.js";
-import * as signals from "ext:deno_os/40_signals.js";
 import * as tty from "ext:runtime/40_tty.js";
-import * as kv from "ext:deno_kv/01_db.ts";
-import * as cron from "ext:deno_cron/01_cron.ts";
 import * as webgpuSurface from "ext:deno_webgpu/02_surface.js";
 import * as telemetry from "ext:deno_telemetry/telemetry.ts";
 import { unstableIds } from "ext:deno_features/flags.js";
@@ -37,6 +32,11 @@ import { bundle } from "ext:deno_bundle_runtime/bundle.ts";
 
 const { ObjectDefineProperties, Float64Array } = primordials;
 
+const loadFfi = core.createLazyLoader("ext:deno_ffi/00_ffi.js");
+const loadFsEvents = core.createLazyLoader("ext:runtime/40_fs_events.js");
+const loadSignals = core.createLazyLoader("ext:deno_os/40_signals.js");
+const loadKv = core.createLazyLoader("ext:deno_kv/01_db.ts");
+const loadCron = core.createLazyLoader("ext:deno_cron/01_cron.ts");
 const loadQuic = core.createLazyLoader("ext:deno_net/03_quic.js");
 const loadWebTransport = core.createLazyLoader("ext:deno_web/webtransport.js");
 
@@ -55,7 +55,7 @@ const denoNs = {
   readTextFileSync: fs.readTextFileSync,
   readFile: fs.readFile,
   readFileSync: fs.readFileSync,
-  watchFs: fsEvents.watchFs,
+  // watchFs is lazy-loaded below via ObjectDefineProperties
   chmodSync: fs.chmodSync,
   chmod: fs.chmod,
   chown: fs.chown,
@@ -145,8 +145,7 @@ const denoNs = {
   utime: fs.utime,
   utimeSync: fs.utimeSync,
   kill: process.kill,
-  addSignalListener: signals.addSignalListener,
-  removeSignalListener: signals.removeSignalListener,
+  // signals are lazy-loaded below via ObjectDefineProperties
   refTimer: timers.refTimer,
   unrefTimer: timers.unrefTimer,
   osRelease: os.osRelease,
@@ -162,17 +161,46 @@ const denoNs = {
   spawn: process.spawn,
   spawnAndWait: process.spawnAndWait,
   spawnAndWaitSync: process.spawnAndWaitSync,
-  dlopen: ffi.dlopen,
-  UnsafeCallback: ffi.UnsafeCallback,
-  UnsafePointer: ffi.UnsafePointer,
-  UnsafePointerView: ffi.UnsafePointerView,
-  UnsafeFnPointer: ffi.UnsafeFnPointer,
+  // FFI is lazy-loaded below via ObjectDefineProperties
   umask: fs.umask,
   HttpClient: httpClient.HttpClient,
   createHttpClient: httpClient.createHttpClient,
   telemetry: telemetry.telemetry,
 };
 
+// Lazy-loaded properties on denoNs.
+ObjectDefineProperties(denoNs, {
+  watchFs: core.propWritableLazyLoaded(
+    (fsEvents) => fsEvents.watchFs,
+    loadFsEvents,
+  ),
+  dlopen: core.propWritableLazyLoaded((ffi) => ffi.dlopen, loadFfi),
+  UnsafeCallback: core.propWritableLazyLoaded(
+    (ffi) => ffi.UnsafeCallback,
+    loadFfi,
+  ),
+  UnsafePointer: core.propWritableLazyLoaded(
+    (ffi) => ffi.UnsafePointer,
+    loadFfi,
+  ),
+  UnsafePointerView: core.propWritableLazyLoaded(
+    (ffi) => ffi.UnsafePointerView,
+    loadFfi,
+  ),
+  UnsafeFnPointer: core.propWritableLazyLoaded(
+    (ffi) => ffi.UnsafeFnPointer,
+    loadFfi,
+  ),
+  addSignalListener: core.propWritableLazyLoaded(
+    (signals) => signals.addSignalListener,
+    loadSignals,
+  ),
+  removeSignalListener: core.propWritableLazyLoaded(
+    (signals) => signals.removeSignalListener,
+    loadSignals,
+  ),
+});
+
 const denoNsUnstableById = { __proto__: null };
 
 denoNsUnstableById[unstableIds.bundle] = {
@@ -181,17 +209,25 @@ denoNsUnstableById[unstableIds.bundle] = {
 
 // denoNsUnstableById[unstableIds.broadcastChannel] = { __proto__: null }
 
-denoNsUnstableById[unstableIds.cron] = {
-  cron: cron.cron,
-};
+denoNsUnstableById[unstableIds.cron] = {};
+ObjectDefineProperties(denoNsUnstableById[unstableIds.cron], {
+  cron: core.propWritableLazyLoaded((cron) => cron.cron, loadCron),
+});
 
-denoNsUnstableById[unstableIds.kv] = {
-  openKv: kv.openKv,
-  AtomicOperation: kv.AtomicOperation,
-  Kv: kv.Kv,
-  KvU64: kv.KvU64,
-  KvListIterator: kv.KvListIterator,
-};
+denoNsUnstableById[unstableIds.kv] = {};
+ObjectDefineProperties(denoNsUnstableById[unstableIds.kv], {
+  openKv: core.propWritableLazyLoaded((kv) => kv.openKv, loadKv),
+  AtomicOperation: core.propWritableLazyLoaded(
+    (kv) => kv.AtomicOperation,
+    loadKv,
+  ),
+  Kv: core.propWritableLazyLoaded((kv) => kv.Kv, loadKv),
+  KvU64: core.propWritableLazyLoaded((kv) => kv.KvU64, loadKv),
+  KvListIterator: core.propWritableLazyLoaded(
+    (kv) => kv.KvListIterator,
+    loadKv,
+  ),
+});
 
 denoNsUnstableById[unstableIds.net] = {
   listenDatagram: net.createListenDatagram(
diff --git a/runtime/shared.rs b/runtime/shared.rs
index 2ab872519b8dab..a300e9ee04da97 100644
--- a/runtime/shared.rs
+++ b/runtime/shared.rs
@@ -31,7 +31,6 @@ extension!(runtime,
     "06_util.js",
     "10_permissions.js",
     "11_workers.js",
-    "40_fs_events.js",
     "40_tty.js",
     "41_prompt.js",
     "90_deno_ns.js",
@@ -39,6 +38,10 @@ extension!(runtime,
     "98_global_scope_window.js",
     "98_global_scope_worker.js"
   ],
+  lazy_loaded_esm = [
+    dir "js",
+    "40_fs_events.js",
+  ],
   customizer = |ext: &mut Extension| {
     #[cfg(not(feature = "exclude_runtime_main_js"))]
     {