diff --git a/.eslintrc.js b/.eslintrc.js
index 20869c5..987b324 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -14,5 +14,5 @@ module.exports = {
     project: ['tsconfig.json'],
   },
 
-  ignorePatterns: ["dist"],
+  ignorePatterns: ['dist'],
 };
diff --git a/README.md b/README.md
index b74ff5e..60cc4bb 100644
--- a/README.md
+++ b/README.md
@@ -7,11 +7,11 @@
 Here are some examples of how to use it:
 
 ```shell
-$ npx -p @geolonia/normalize-any-latlng normalize-any-latlng '29°31′55″N 35°00′20″E' # 29.531944444444445 35.00555555555555
-$ npx -p @geolonia/normalize-any-latlng normalize-any-latlng '북위37°34′00″ 동경126°58′41″' # 37.56666666666667 126.97805555555556
-$ npx -p @geolonia/normalize-any-latlng normalize-any-latlng '남위34°36′12″ 서경58°22′54″' # -34.60333333333333 -58.38166666666667
-$ npx -p @geolonia/normalize-any-latlng normalize-any-latlng '北緯32度53分9.35秒 東経130度11分9.34秒' # 32.885930555555554 130.18592777777778
-$ npx -p @geolonia/normalize-any-latlng normalize-any-latlng '45°24′N 75°40′W' # 45.4 -75.66666666666667
+$ npx @geolonia/normalize-any-latlng '29°31′55″N 35°00′20″E' # 29.531944444444445 35.00555555555555
+$ npx @geolonia/normalize-any-latlng '북위37°34′00″ 동경126°58′41″' # 37.56666666666667 126.97805555555556
+$ npx @geolonia/normalize-any-latlng '남위34°36′12″ 서경58°22′54″' # -34.60333333333333 -58.38166666666667
+$ npx @geolonia/normalize-any-latlng '北緯32度53分9.35秒 東経130度11分9.34秒' # 32.885930555555554 130.18592777777778
+$ npx @geolonia/normalize-any-latlng '45°24′N 75°40′W' # 45.4 -75.66666666666667
 ```
 
 You can see more normalization examples in [src/index.test.ts](./src/index.test.ts).
diff --git a/rollup.config.js b/rollup.config.js
index 9aa0c19..30a71ef 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -10,7 +10,10 @@ const plugins = [
   commonjs({
     requireReturnsDefault: 'auto',
   }),
-  typescript({ useTsconfigDeclarationDir: true }),
+  typescript({
+    useTsconfigDeclarationDir: true,
+    tsconfig: 'tsconfig.prod.json',
+  }),
 ];
 
 export default [
diff --git a/tsconfig.json b/tsconfig.json
index c5311fb..c5ea0cc 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -17,7 +17,6 @@
   ],
   "exclude": [
     "./dist/",
-    "./src/**/*.test.ts",
     "./node_modules/"
   ]
 }
diff --git a/tsconfig.prod.json b/tsconfig.prod.json
new file mode 100644
index 0000000..539eb64
--- /dev/null
+++ b/tsconfig.prod.json
@@ -0,0 +1,6 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": [
+    "./src/**/*.test.ts",
+  ]
+}