diff --git a/README.md b/README.md
index 11e463b..52468db 100644
--- a/README.md
+++ b/README.md
@@ -27,6 +27,27 @@ VAT, Person and Tax identifiers.
 
 All country validators are in the "namespace" of the ISO country code.
 
+## Bundle size: tree-shakeable imports
+
+The `stdnum` object eagerly references every country, so importing it bundles
+all of them (~200KB minified). If you only need a few validators, use either of
+these forms instead:
+
+    // Named country exports — tree-shakeable, bundlers drop unused countries
+    import { GB, BR } from 'stdnum';
+
+    GB.nino.validate('AB123456C');
+    BR.cpf.validate('390.533.447-05');
+
+    // Or import a single validator via its subpath
+    import { validate } from 'stdnum/gb/nino';
+
+    validate('AB123456C');
+
+Subpaths follow the source layout: `stdnum/<country>/<number>` (e.g.
+`stdnum/it/codicefiscale`), and `stdnum/<country>` for a whole country's
+validators.
+
 ## Supported Countries and Numbers
 
 How you can help! This library currently support about half the countries in the world. It would be great if we can get to 100%. Submit an issue with any reference documentation and I'll do my best to integrate it, bonus points if you can get detailed descriptions of checksums or other validation criteria.
diff --git a/package.json b/package.json
index e689865..50cc613 100644
--- a/package.json
+++ b/package.json
@@ -11,10 +11,25 @@
   "main": "./lib/cjs/index.js",
   "module": "./lib/esm/index.js",
   "types": "./lib/cjs/index.d.ts",
-  "exports_NOT_YET": {
-    "./": {
-      "import": "./lib/esm/",
-      "require": "./lib/cjs/"
+  "sideEffects": false,
+  "exports": {
+    ".": {
+      "types": "./lib/cjs/index.d.ts",
+      "node": "./lib/cjs/index.js",
+      "import": "./lib/esm/index.js",
+      "default": "./lib/cjs/index.js"
+    },
+    "./package.json": "./package.json",
+    "./lib/esm/*.js": "./lib/esm/*.js",
+    "./lib/esm/*": "./lib/esm/*.js",
+    "./lib/cjs/*.js": "./lib/cjs/*.js",
+    "./lib/cjs/*": "./lib/cjs/*.js",
+    "./src/*": "./src/*",
+    "./*": {
+      "types": "./lib/esm/*.d.ts",
+      "node": "./lib/cjs/*.js",
+      "import": "./lib/esm/*.js",
+      "default": "./lib/cjs/*.js"
     }
   },
   "overrides": {
diff --git a/src/index.ts b/src/index.ts
index 082fdda..710ae19 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -95,6 +95,106 @@ import type { Validator } from './types';
 
 export type { Validator } from './types';
 
+// Named per-country exports. Unlike the `stdnum` object below (which eagerly
+// references every country and therefore always bundles all of them), these are
+// tree-shakeable: `import { GB } from 'stdnum'` lets a bundler drop the other
+// countries entirely.
+export {
+  AD,
+  AI,
+  AL,
+  AO,
+  AR,
+  AT,
+  AU,
+  AZ,
+  BA,
+  BE,
+  BG,
+  BO,
+  BR,
+  BY,
+  BZ,
+  CA,
+  CH,
+  CL,
+  CN,
+  CO,
+  CR,
+  CU,
+  CY,
+  CZ,
+  DE,
+  DK,
+  DO,
+  DZ,
+  EC,
+  EE,
+  EG,
+  ES,
+  FI,
+  FO,
+  FR,
+  GB,
+  GH,
+  GR,
+  GN,
+  GT,
+  HK,
+  HR,
+  HU,
+  ID,
+  IE,
+  IL,
+  IN,
+  IS,
+  IT,
+  JP,
+  KE,
+  KR,
+  LI,
+  LT,
+  LU,
+  LV,
+  MA,
+  MC,
+  MD,
+  ME,
+  MK,
+  MT,
+  MU,
+  MX,
+  MY,
+  MZ,
+  NL,
+  NO,
+  NZ,
+  PE,
+  PK,
+  PL,
+  PT,
+  PY,
+  RO,
+  RS,
+  RU,
+  SE,
+  SG,
+  SI,
+  SK,
+  SM,
+  SV,
+  TH,
+  TN,
+  TR,
+  TW,
+  UA,
+  US,
+  UY,
+  VE,
+  VN,
+  ZA,
+};
+
 // Live an uppercase world, to prevent keyword collisions
 export const stdnum: Record<string, Record<string, Validator>> = {
   AD,