diff --git a/src/lib/transpiler/babel.ts b/src/lib/transpiler/babel.ts
index 119d4bb..0fd59d0 100644
--- a/src/lib/transpiler/babel.ts
+++ b/src/lib/transpiler/babel.ts
@@ -1,16 +1,18 @@
 import { SourceMap } from "./map.ts";
-import { transform } from "@babel/standalone";
-// import presetEnv from "@babel/preset-env";
+import { transform, availablePresets } from "@babel/standalone";
 
 export default function babel(next: Compiler): Compiler {
 	print("Loaded babel!");
-	
+
 	return (filename, code, prevMap) => {
 		const res = transform(code, {
 			filename,
 			sourceMaps: true,
+			presets: [availablePresets.env],
 		});
 
+		print(res.map!.mappings);
+
 		const map = SourceMap.parse({
 			file: "babel-internal://" + filename,
 			mappings: res.map!.mappings,
diff --git a/src/lib/transpiler/map.ts b/src/lib/transpiler/map.ts
index e30d39b..915cf66 100644
--- a/src/lib/transpiler/map.ts
+++ b/src/lib/transpiler/map.ts
@@ -11,10 +11,21 @@ export type Location = readonly [file: string, line: number, start: number];
 export function decodeVLQ(val: string): number[][][] {
 	const lines: number[][][] = [];
 
-	for (const line of val.split(";", -1)) {
-		const elements: number[][] = [];
+	const fileParts = val.split(";", -1);
+
+	for (let i = 0; i < fileParts.length; i++) {
+		const line = fileParts[i];
+		if (line.length === 0) {
+			lines.push([]);
+			continue;
+		}
+
+		const elements: number[][] = [];
+		const lineParts = line.split(",", -1);
+
+		for (let i = 0; i < lineParts.length; i++) {
+			const el = lineParts[i];
 
-		for (const el of line.split(",", -1)) {
 			if (el.length === 0) elements.push([]);
 			else {
 				const list: number[] = [];
@@ -98,7 +109,7 @@ export class VLQSourceMap {
 				const mid = (a + b) >> 1;
 				const el = line[mid];
 
-				const cmp = el[0] - src[1];
+				const cmp = el[0] - src[2];
 
 				if (cmp < 0) {
 					if (done) {
@@ -132,10 +143,13 @@ export class VLQSourceMap {
 		const lastCols = new Set<number>();
 
 		for (let compiledRow = 0; compiledRow < mapping.length; compiledRow++) {
-			const line = file[compiledRow] ??= [];
+			const line: [start: number, dst: Location][] = file[compiledRow] = [];
 			let compiledCol = 0;
 
-			for (const rawSeg of mapping[compiledRow]) {
+			const rowData = mapping[compiledRow];
+			for (let i = 0; i < rowData.length; i++) {
+				const rawSeg = rowData[i];
+
 				compiledCol += rawSeg.length > 0 ? rawSeg[0] : 0;
 				originalFile += rawSeg.length > 1 ? rawSeg[1] : 0;
 				originalRow += rawSeg.length > 2 ? rawSeg[2] : 0;
diff --git a/src/main/tsconfig.json b/src/main/tsconfig.json
new file mode 100644
index 0000000..d7d4524
--- /dev/null
+++ b/src/main/tsconfig.json
@@ -0,0 +1,17 @@
+{
+    "include": ["resources/lib/**/*.ts", "resources/lib/values/.number.d.ts"],
+    "compilerOptions": {
+        "strict": true,
+        "esModuleInterop": true,
+        "skipLibCheck": true,
+        "moduleResolution": "Bundler",
+        "module": "ESNext",
+        "target": "ESNext",
+        "lib": [],
+        "forceConsistentCasingInFileNames": true,
+        "emitDecoratorMetadata": true,
+        "experimentalDecorators": true,
+        "allowImportingTsExtensions": true,
+        "noEmit": true
+    }
+}