diff --git a/.gitignore b/.gitignore
index b25c15b..dc30bb8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 *~
+node_modules
+obj/**/*.js
diff --git a/obj/package.json b/obj/package.json
new file mode 100644
index 0000000..5ffd980
--- /dev/null
+++ b/obj/package.json
@@ -0,0 +1 @@
+{ "type": "module" }
diff --git a/src/steps/one.ts b/src/steps/one.ts
index b9b3f86..a9f0eab 100644
--- a/src/steps/one.ts
+++ b/src/steps/one.ts
@@ -1,4 +1,4 @@
-import { useTypes } from 'over.ts/src/index';
+import { useTypes } from 'over.ts/src/index.js';
 
 const types = {
    number: (x: unknown): x is number => typeof x === 'number',
diff --git a/tsconfig.json b/tsconfig.json
index d17d548..5741128 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,7 +1,9 @@
 {
     "compilerOptions": {
         "target": "ES2022",
-        "moduleResolution": "node"
+        "moduleResolution": "node",
+        "rootDir": "src",
+        "outDir": "obj"
     },
     "files": [
         "src/steps/one.ts"