diff --git a/.changeset/long-humans-jump.md b/.changeset/long-humans-jump.md
new file mode 100644
index 0000000000..02c550dac9
--- /dev/null
+++ b/.changeset/long-humans-jump.md
@@ -0,0 +1,10 @@
+---
+"@siteimprove/alfa-applicative": patch
+"@siteimprove/alfa-collection": patch
+"@siteimprove/alfa-foldable": patch
+"@siteimprove/alfa-functor": patch
+"@siteimprove/alfa-mapper": patch
+"@siteimprove/alfa-monad": patch
+---
+
+**Changed:** Packages that only export type now only pack their `.d.ts` files.
diff --git a/packages/alfa-applicative/package.json b/packages/alfa-applicative/package.json
index c41402e6da..929d7bc236 100644
--- a/packages/alfa-applicative/package.json
+++ b/packages/alfa-applicative/package.json
@@ -15,10 +15,8 @@
     "node": ">=20.0.0"
   },
   "type": "module",
-  "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "files": [
-    "dist/**/*.js",
     "dist/**/*.d.ts"
   ],
   "dependencies": {
diff --git a/packages/alfa-applicative/src/index.ts b/packages/alfa-applicative/src/index.ts
index 1e4b0f5485..82f05626fd 100644
--- a/packages/alfa-applicative/src/index.ts
+++ b/packages/alfa-applicative/src/index.ts
@@ -4,4 +4,4 @@
  *
  * @packageDocumentation
  */
-export * from "./applicative.js";
+export type * from "./applicative.js";
diff --git a/packages/alfa-applicative/src/tsconfig.json b/packages/alfa-applicative/src/tsconfig.json
index 7b51e6c634..ceaca51090 100644
--- a/packages/alfa-applicative/src/tsconfig.json
+++ b/packages/alfa-applicative/src/tsconfig.json
@@ -1,7 +1,7 @@
 {
   "$schema": "http://json.schemastore.org/tsconfig",
   "extends": "../tsconfig.json",
-  "compilerOptions": { "outDir": "../dist" },
+  "compilerOptions": { "outDir": "../dist", "emitDeclarationOnly": true },
   "files": ["./applicative.ts", "./index.ts"],
   "references": [
     { "path": "../../alfa-functor" },
diff --git a/packages/alfa-collection/package.json b/packages/alfa-collection/package.json
index bd8d312bf6..de430e8fc3 100644
--- a/packages/alfa-collection/package.json
+++ b/packages/alfa-collection/package.json
@@ -15,10 +15,8 @@
     "node": ">=20.0.0"
   },
   "type": "module",
-  "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "files": [
-    "dist/**/*.js",
     "dist/**/*.d.ts"
   ],
   "dependencies": {
diff --git a/packages/alfa-collection/src/index.ts b/packages/alfa-collection/src/index.ts
index 6e6cb2a2b8..9d79b1648d 100644
--- a/packages/alfa-collection/src/index.ts
+++ b/packages/alfa-collection/src/index.ts
@@ -1 +1 @@
-export * from "./collection.js";
+export type * from "./collection.js";
diff --git a/packages/alfa-collection/src/tsconfig.json b/packages/alfa-collection/src/tsconfig.json
index 319df380d2..2d127fa9c1 100644
--- a/packages/alfa-collection/src/tsconfig.json
+++ b/packages/alfa-collection/src/tsconfig.json
@@ -1,7 +1,7 @@
 {
   "$schema": "http://json.schemastore.org/tsconfig",
   "extends": "../tsconfig.json",
-  "compilerOptions": { "outDir": "../dist" },
+  "compilerOptions": { "outDir": "../dist", "emitDeclarationOnly": true },
   "files": ["./collection.ts", "./index.ts"],
   "references": [
     { "path": "../../alfa-applicative" },
diff --git a/packages/alfa-foldable/package.json b/packages/alfa-foldable/package.json
index eef64b9ffd..c8a69a808d 100644
--- a/packages/alfa-foldable/package.json
+++ b/packages/alfa-foldable/package.json
@@ -15,10 +15,8 @@
     "node": ">=20.0.0"
   },
   "type": "module",
-  "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "files": [
-    "dist/**/*.js",
     "dist/**/*.d.ts"
   ],
   "dependencies": {
diff --git a/packages/alfa-foldable/src/index.ts b/packages/alfa-foldable/src/index.ts
index e7d69e097c..0ccd95a656 100644
--- a/packages/alfa-foldable/src/index.ts
+++ b/packages/alfa-foldable/src/index.ts
@@ -1 +1 @@
-export * from "./foldable.js";
+export type * from "./foldable.js";
diff --git a/packages/alfa-foldable/src/tsconfig.json b/packages/alfa-foldable/src/tsconfig.json
index 7bbc0b493c..92e23b906d 100644
--- a/packages/alfa-foldable/src/tsconfig.json
+++ b/packages/alfa-foldable/src/tsconfig.json
@@ -1,7 +1,7 @@
 {
   "$schema": "http://json.schemastore.org/tsconfig",
   "extends": "../tsconfig.json",
-  "compilerOptions": { "outDir": "../dist" },
+  "compilerOptions": { "outDir": "../dist", "emitDeclarationOnly": true },
   "files": ["./foldable.ts", "./index.ts"],
   "references": [{ "path": "../../alfa-reducer" }]
 }
diff --git a/packages/alfa-functor/package.json b/packages/alfa-functor/package.json
index ef902f6e57..57a79513ea 100644
--- a/packages/alfa-functor/package.json
+++ b/packages/alfa-functor/package.json
@@ -15,10 +15,8 @@
     "node": ">=20.0.0"
   },
   "type": "module",
-  "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "files": [
-    "dist/**/*.js",
     "dist/**/*.d.ts"
   ],
   "dependencies": {
diff --git a/packages/alfa-functor/src/index.ts b/packages/alfa-functor/src/index.ts
index eefd62ba84..4d749fac14 100644
--- a/packages/alfa-functor/src/index.ts
+++ b/packages/alfa-functor/src/index.ts
@@ -1 +1 @@
-export * from "./functor.js";
+export type * from "./functor.js";
diff --git a/packages/alfa-functor/src/tsconfig.json b/packages/alfa-functor/src/tsconfig.json
index c17f30e2e6..5b07e36f60 100644
--- a/packages/alfa-functor/src/tsconfig.json
+++ b/packages/alfa-functor/src/tsconfig.json
@@ -1,7 +1,7 @@
 {
   "$schema": "http://json.schemastore.org/tsconfig",
   "extends": "../tsconfig.json",
-  "compilerOptions": { "outDir": "../dist" },
+  "compilerOptions": { "outDir": "../dist", "emitDeclarationOnly": true },
   "files": ["./functor.ts", "./index.ts"],
   "references": [{ "path": "../../alfa-mapper" }]
 }
diff --git a/packages/alfa-mapper/package.json b/packages/alfa-mapper/package.json
index cb7d522ac4..176c4b07c0 100644
--- a/packages/alfa-mapper/package.json
+++ b/packages/alfa-mapper/package.json
@@ -15,10 +15,8 @@
     "node": ">=20.0.0"
   },
   "type": "module",
-  "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "files": [
-    "dist/**/*.js",
     "dist/**/*.d.ts"
   ],
   "publishConfig": {
diff --git a/packages/alfa-mapper/src/index.ts b/packages/alfa-mapper/src/index.ts
index 9447ffd690..de1335c647 100644
--- a/packages/alfa-mapper/src/index.ts
+++ b/packages/alfa-mapper/src/index.ts
@@ -1 +1 @@
-export * from "./mapper.js";
+export type * from "./mapper.js";
diff --git a/packages/alfa-mapper/src/tsconfig.json b/packages/alfa-mapper/src/tsconfig.json
index d4d2270128..f9e8d05638 100644
--- a/packages/alfa-mapper/src/tsconfig.json
+++ b/packages/alfa-mapper/src/tsconfig.json
@@ -1,6 +1,6 @@
 {
   "$schema": "http://json.schemastore.org/tsconfig",
   "extends": "../tsconfig.json",
-  "compilerOptions": { "outDir": "../dist" },
+  "compilerOptions": { "outDir": "../dist", "emitDeclarationOnly": true },
   "files": ["./index.ts", "./mapper.ts"]
 }
diff --git a/packages/alfa-monad/package.json b/packages/alfa-monad/package.json
index 51dffac87f..e93247c580 100644
--- a/packages/alfa-monad/package.json
+++ b/packages/alfa-monad/package.json
@@ -15,10 +15,8 @@
     "node": ">=20.0.0"
   },
   "type": "module",
-  "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "files": [
-    "dist/**/*.js",
     "dist/**/*.d.ts"
   ],
   "dependencies": {
diff --git a/packages/alfa-monad/src/index.ts b/packages/alfa-monad/src/index.ts
index 4d3874a395..7ac6e9fdcb 100644
--- a/packages/alfa-monad/src/index.ts
+++ b/packages/alfa-monad/src/index.ts
@@ -1 +1 @@
-export * from "./monad.js";
+export type * from "./monad.js";
diff --git a/packages/alfa-monad/src/tsconfig.json b/packages/alfa-monad/src/tsconfig.json
index cec08aa259..ec727a71fd 100644
--- a/packages/alfa-monad/src/tsconfig.json
+++ b/packages/alfa-monad/src/tsconfig.json
@@ -1,7 +1,7 @@
 {
   "$schema": "http://json.schemastore.org/tsconfig",
   "extends": "../tsconfig.json",
-  "compilerOptions": { "outDir": "../dist" },
+  "compilerOptions": { "outDir": "../dist", "emitDeclarationOnly": true },
   "files": ["./index.ts", "./monad.ts"],
   "references": [
     { "path": "../../alfa-applicative" },