diff --git a/rollup.config.js b/rollup.config.js
index a0f1aea..96e13a4 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -12,6 +12,7 @@ const config = {
     name: "esptooljs",
     file: 'bundle.js',
     format: 'es',
+    inlineDynamicImports: true
   },
   plugins: [
     resolve(),
diff --git a/src/esploader.ts b/src/esploader.ts
index 3822874..db58731 100644
--- a/src/esploader.ts
+++ b/src/esploader.ts
@@ -1,25 +1,34 @@
 import { ESPError } from "./error";
 import { inflate, deflate } from "pako";
-import ESP32ROM from "./targets/esp32";
 import { Transport } from "./webserial";
 import { ROM } from "./targets/rom";
-import ESP32C3ROM from "./targets/esp32c3";
-import ESP32S3ROM from "./targets/esp32s3";
-import ESP32S2ROM from "./targets/esp32s2";
-import ESP8266ROM from "./targets/esp8266";
 
-const MAGIC_TO_CHIP: { [key: number]: ROM } = {
-  0x00f01d83: new ESP32ROM(),
-  0x6921506f: new ESP32C3ROM(), // ECO 1+2
-  0x1b31506f: new ESP32C3ROM(), //ECO 3
-  0x09: new ESP32S3ROM(),
-  0x000007c6: new ESP32S2ROM(),
-  0xfff0c101: new ESP8266ROM(),
-};
-
-export interface ESPBinFile {
-  data: string;
-  address: number;
+async function magic2Chip(magic: number): Promise<ROM> {
+  switch (magic) {
+    case 0x00f01d83: {
+      const { ESP32ROM } = await import("./targets/esp32");
+      return new ESP32ROM();
+    }
+    case 0x6921506f:
+    case 0x1b31506f: {
+      const { ESP32C3ROM } = await import("./targets/esp32c3");
+      return new ESP32C3ROM();
+    }
+    case 0x09: {
+      const { ESP32S3ROM } = await import("./targets/esp32s3");
+      return new ESP32S3ROM();
+    }
+    case 0x000007c6: {
+      const { ESP32S2ROM } = await import("./targets/esp32s2");
+      return new ESP32S2ROM();
+    }
+    case 0xfff0c101: {
+      const { ESP8266ROM } = await import("./targets/esp8266");
+      return new ESP8266ROM();
+    }
+    default:
+      return null;
+  }
 }
 
 export interface IEspLoaderTerminal {
@@ -307,7 +316,7 @@ export class ESPLoader {
     while (i--) {
       try {
         const resp = await this.sync();
-        this.log(resp[0].toString(0));
+        this.log(resp[0].toString());
         return "success";
       } catch (error) {
         this.log(error);
@@ -349,10 +358,8 @@ export class ESPLoader {
     if (!detecting) {
       const chip_magic_value = (await this.read_reg(0x40001000)) >>> 0;
       this.log("Chip Magic " + chip_magic_value.toString(16));
-
-      if (chip_magic_value in MAGIC_TO_CHIP) {
-        this.chip = MAGIC_TO_CHIP[chip_magic_value];
-      } else {
+      this.chip = await magic2Chip(chip_magic_value);
+      if (this.chip === null) {
         throw new ESPError(`Unexpected CHIP magic value ${chip_magic_value}. Failed to autodetect chip type.`);
       }
     }
@@ -840,7 +847,10 @@ export class ESPLoader {
   }
 
   async write_flash(
-    fileArray: ESPBinFile[],
+    fileArray: {
+      data: string;
+      address: number;
+    }[],
     flash_size = "keep",
     flash_mode = "keep",
     flash_freq = "keep",
diff --git a/src/index.ts b/src/index.ts
index 227e0f8..2f01753 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,2 +1,2 @@
-export { IEspLoaderTerminal, ESPLoader, ESPBinFile } from "./esploader";
+export { IEspLoaderTerminal, ESPLoader } from "./esploader";
 export { Transport } from "./webserial";
diff --git a/src/targets/esp32.ts b/src/targets/esp32.ts
index b0c75f0..2c36fb0 100644
--- a/src/targets/esp32.ts
+++ b/src/targets/esp32.ts
@@ -1,7 +1,7 @@
 import { ESPLoader } from "../esploader";
 import { ROM } from "./rom";
 
-export default class ESP32ROM extends ROM {
+export class ESP32ROM extends ROM {
   public CHIP_NAME = "ESP32";
   public IMAGE_CHIP_ID = 0;
   public EFUSE_RD_REG_BASE = 0x3ff5a000;
diff --git a/src/targets/esp32c3.ts b/src/targets/esp32c3.ts
index 77eefdf..1c1f804 100644
--- a/src/targets/esp32c3.ts
+++ b/src/targets/esp32c3.ts
@@ -1,7 +1,7 @@
 import { ESPLoader } from "../esploader";
 import { ROM } from "./rom";
 
-export default class ESP32C3ROM extends ROM {
+export class ESP32C3ROM extends ROM {
   public CHIP_NAME = "ESP32-C3";
   public IMAGE_CHIP_ID = 5;
   public EFUSE_BASE = 0x60008800;
diff --git a/src/targets/esp32s2.ts b/src/targets/esp32s2.ts
index 814fdc7..0b220f6 100644
--- a/src/targets/esp32s2.ts
+++ b/src/targets/esp32s2.ts
@@ -1,7 +1,7 @@
 import { ESPLoader } from "../esploader";
 import { ROM } from "./rom";
 
-export default class ESP32S2ROM extends ROM {
+export class ESP32S2ROM extends ROM {
   public CHIP_NAME = "ESP32-S2";
   public IMAGE_CHIP_ID = 2;
   public MAC_EFUSE_REG = 0x3f41a044;
diff --git a/src/targets/esp32s3.ts b/src/targets/esp32s3.ts
index 4274f3d..2e184a3 100644
--- a/src/targets/esp32s3.ts
+++ b/src/targets/esp32s3.ts
@@ -1,7 +1,7 @@
 import { ESPLoader } from "../esploader";
 import { ROM } from "./rom";
 
-export default class ESP32S3ROM extends ROM {
+export class ESP32S3ROM extends ROM {
   public CHIP_NAME = "ESP32-S3";
   public IMAGE_CHIP_ID = 9;
   public EFUSE_BASE = 0x60007000;
diff --git a/src/targets/esp8266.ts b/src/targets/esp8266.ts
index f34a76a..81a2af4 100644
--- a/src/targets/esp8266.ts
+++ b/src/targets/esp8266.ts
@@ -1,7 +1,7 @@
 import { ESPLoader } from "../esploader";
 import { ROM } from "./rom";
 
-export default class ESP8266ROM extends ROM {
+export class ESP8266ROM extends ROM {
   public CHIP_NAME = "ESP8266";
   public CHIP_DETECT_MAGIC_VALUE = [0xfff0c101];
   public EFUSE_RD_REG_BASE = 0x3ff00050;