diff --git a/test/cases/loaders/package-type/loader.cjs b/test/cases/loaders/package-type/loader.cjs
index 8320d084373..94974dcfad5 100644
--- a/test/cases/loaders/package-type/loader.cjs
+++ b/test/cases/loaders/package-type/loader.cjs
@@ -1,3 +1,4 @@
+/** @type {import("../../../../").LoaderDefinition} */
 module.exports = function loader() {
 	return `module.exports = "${this.loaders[this.loaderIndex].type}";`;
 };
diff --git a/test/cases/loaders/package-type/loader.js b/test/cases/loaders/package-type/loader.js
index 0339415ccb7..94974dcfad5 100644
--- a/test/cases/loaders/package-type/loader.js
+++ b/test/cases/loaders/package-type/loader.js
@@ -1,3 +1,4 @@
-export default function loader() {
-	return `export default "${this.loaders[this.loaderIndex].type}";`;
-}
+/** @type {import("../../../../").LoaderDefinition} */
+module.exports = function loader() {
+	return `module.exports = "${this.loaders[this.loaderIndex].type}";`;
+};
diff --git a/test/cases/loaders/package-type/loader.mjs b/test/cases/loaders/package-type/loader.mjs
index 0339415ccb7..58914cd70e5 100644
--- a/test/cases/loaders/package-type/loader.mjs
+++ b/test/cases/loaders/package-type/loader.mjs
@@ -1,3 +1,4 @@
+/** @type {import("../../../../").LoaderDefinition} */
 export default function loader() {
 	return `export default "${this.loaders[this.loaderIndex].type}";`;
 }
diff --git a/test/cases/loaders/package-type/node_modules/cjs/loader.cjs b/test/cases/loaders/package-type/node_modules/cjs/loader.cjs
index 8320d084373..b47e68eb16c 100644
--- a/test/cases/loaders/package-type/node_modules/cjs/loader.cjs
+++ b/test/cases/loaders/package-type/node_modules/cjs/loader.cjs
@@ -1,3 +1,4 @@
+/** @type {import("../../../../../../").LoaderDefinition} */
 module.exports = function loader() {
 	return `module.exports = "${this.loaders[this.loaderIndex].type}";`;
 };
diff --git a/test/cases/loaders/package-type/node_modules/cjs/loader.js b/test/cases/loaders/package-type/node_modules/cjs/loader.js
index 8320d084373..b47e68eb16c 100644
--- a/test/cases/loaders/package-type/node_modules/cjs/loader.js
+++ b/test/cases/loaders/package-type/node_modules/cjs/loader.js
@@ -1,3 +1,4 @@
+/** @type {import("../../../../../../").LoaderDefinition} */
 module.exports = function loader() {
 	return `module.exports = "${this.loaders[this.loaderIndex].type}";`;
 };
diff --git a/test/cases/loaders/package-type/node_modules/cjs/loader.mjs b/test/cases/loaders/package-type/node_modules/cjs/loader.mjs
index 0339415ccb7..35c1f17332d 100644
--- a/test/cases/loaders/package-type/node_modules/cjs/loader.mjs
+++ b/test/cases/loaders/package-type/node_modules/cjs/loader.mjs
@@ -1,3 +1,4 @@
+/** @type {import("../../../../../../").LoaderDefinition} */
 export default function loader() {
 	return `export default "${this.loaders[this.loaderIndex].type}";`;
 }
diff --git a/test/cases/loaders/package-type/node_modules/esm/loader.cjs b/test/cases/loaders/package-type/node_modules/esm/loader.cjs
index 8320d084373..b47e68eb16c 100644
--- a/test/cases/loaders/package-type/node_modules/esm/loader.cjs
+++ b/test/cases/loaders/package-type/node_modules/esm/loader.cjs
@@ -1,3 +1,4 @@
+/** @type {import("../../../../../../").LoaderDefinition} */
 module.exports = function loader() {
 	return `module.exports = "${this.loaders[this.loaderIndex].type}";`;
 };
diff --git a/test/cases/loaders/package-type/node_modules/esm/loader.js b/test/cases/loaders/package-type/node_modules/esm/loader.js
index 0339415ccb7..35c1f17332d 100644
--- a/test/cases/loaders/package-type/node_modules/esm/loader.js
+++ b/test/cases/loaders/package-type/node_modules/esm/loader.js
@@ -1,3 +1,4 @@
+/** @type {import("../../../../../../").LoaderDefinition} */
 export default function loader() {
 	return `export default "${this.loaders[this.loaderIndex].type}";`;
 }
diff --git a/test/cases/loaders/package-type/node_modules/esm/loader.mjs b/test/cases/loaders/package-type/node_modules/esm/loader.mjs
index 0339415ccb7..35c1f17332d 100644
--- a/test/cases/loaders/package-type/node_modules/esm/loader.mjs
+++ b/test/cases/loaders/package-type/node_modules/esm/loader.mjs
@@ -1,3 +1,4 @@
+/** @type {import("../../../../../../").LoaderDefinition} */
 export default function loader() {
 	return `export default "${this.loaders[this.loaderIndex].type}";`;
 }