diff --git a/tsconfig.json b/tsconfig.json
index af0b0794..d69aa7db 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,11 +1,39 @@
 {
+	"compilerOptions": {
+		"moduleResolution": "node",
+		"module": "es2020",
+		"lib": ["es2020", "ESNext", "DOM.Iterable", "DOM"],
+		"target": "es2019",
+		/**
+			svelte-preprocess cannot figure out whether you have a value or a type, so tell TypeScript
+			to enforce using \`import type\` instead of \`import\` for Types.
+			*/
+		"importsNotUsedAsValues": "error",
+		"isolatedModules": true,
+		"resolveJsonModule": true,
+		/**
+			To have warnings/errors of the Svelte compiler at the correct position,
+			enable source maps by default.
+			*/
+		"sourceMap": true,
+		"esModuleInterop": true,
+		"skipLibCheck": true,
+		"forceConsistentCasingInFileNames": true,
+		"baseUrl": ".",
+		"allowJs": true,
+		"checkJs": true,
+		"paths": {
+			"$lib": ["src/lib"],
+			"$lib/*": ["src/lib/*"]
+		}
+	},
 	"include": [
 		"src/**/*.d.ts",
+		"src/**/*.js",
 		"src/**/*.ts",
 		"src/**/*.svelte",
 		"cypress/**/*.ts",
 		"cypress/**/*.js",
 		"static/**/*.js"
-	],
-	"extends": "./.svelte-kit/tsconfig.json"
+	]
 }