diff --git a/package.json b/package.json
index 8b42a9ddd..02d99c431 100644
--- a/package.json
+++ b/package.json
@@ -14,11 +14,15 @@
   },
   "dependencies": {
     "rollup": "^2.8.2",
-    "rollup-plugin-esbuild": "^1.2.0"
+    "rollup-plugin-esbuild": "^1.3.1"
   },
   "devDependencies": {
+    "@rollup/plugin-commonjs": "^11.1.0",
     "@types/node": "^13.9.2",
+    "@types/resolve": "^1.17.0",
     "cac": "^6.5.8",
+    "colorette": "^1.1.0",
+    "resolve": "^1.17.0",
     "rollup-plugin-hashbang": "^2.2.2",
     "typescript": "^3.8.3"
   }
diff --git a/src/cli.ts b/src/cli.ts
index 679357ff7..69e2cbc50 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -2,6 +2,7 @@
 import { readFileSync } from 'fs'
 import { join } from 'path'
 import { cac } from 'cac'
+import { handlError } from './errors'
 
 const cli = cac('tsup')
 
@@ -15,22 +16,43 @@ cli
   .option('--target <target>', 'Bundle target, "es20XX" or "esnext"', {
     default: 'es2017',
   })
+  .option('--watch', 'Watch mode')
   .action(async (files: string[], options) => {
-    const { rollup } = await import('rollup')
+    const { rollup, watch } = await import('rollup')
     const { default: hashbangPlugin } = await import('rollup-plugin-hashbang')
     const { default: esbuildPlugin } = await import('rollup-plugin-esbuild')
+    const { default: commonjsPlugin } = await import('@rollup/plugin-commonjs')
+    const { resolvePlugin } = await import('./resolve-plugin')
 
-    const result = await rollup({
+    const inputOptions = {
       input: files,
       plugins: [
         hashbangPlugin(),
+        resolvePlugin(),
+        commonjsPlugin(),
         esbuildPlugin({ minify: options.minify, target: options.target }),
       ],
-    })
-    await result.write({
+    }
+    const outputOptions = {
       dir: options.outDir,
       format: options.format,
-    })
+    }
+    if (options.watch) {
+      const watcher = watch({
+        ...inputOptions,
+        output: outputOptions,
+      })
+      watcher.on('event', (event) => {
+        console.log(event)
+      })
+    } else {
+      try {
+        const result = await rollup(inputOptions)
+        await result.write(outputOptions)
+      } catch (error) {
+        handlError(error)
+      }
+    }
   })
 
 cli.help()
@@ -38,4 +60,8 @@ cli.help()
 const pkgPath = join(__dirname, '../package.json')
 cli.version(JSON.parse(readFileSync(pkgPath, 'utf8')).version)
 
-cli.parse()
+try {
+  cli.parse()
+} catch (error) {
+  handlError(error)
+}
diff --git a/src/errors.ts b/src/errors.ts
new file mode 100644
index 000000000..a5dcf3338
--- /dev/null
+++ b/src/errors.ts
@@ -0,0 +1,11 @@
+import colors from 'colorette'
+
+export function handlError(error: any) {
+  if (error.frame) {
+    console.error(colors.red(`Error parsing: ${error.loc.file}:${error.loc.line}:${error.loc.column}`))
+    console.error(colors.dim(error.frame))
+  } else {
+    console.error(colors.red(error.stack))
+  }
+  process.exitCode = 1
+}
\ No newline at end of file
diff --git a/src/resolve-plugin.ts b/src/resolve-plugin.ts
new file mode 100644
index 000000000..4aa0c9bbb
--- /dev/null
+++ b/src/resolve-plugin.ts
@@ -0,0 +1,36 @@
+import {builtinModules} from 'module'
+import { dirname } from 'path'
+import { Plugin } from 'rollup'
+import r, { Opts as ResolveOpts } from 'resolve'
+
+const resolvePackage = (id: string, options: ResolveOpts): Promise<string> =>
+  new Promise((resolve, reject) => {
+    r(id, options, (err, result) => {
+      if (err) {
+        return reject(err)
+      }
+      resolve(result)
+    })
+  })
+
+const PACKAGE_NAME_RE = /^[@a-z]/
+
+export const resolvePlugin = (): Plugin => {
+  return {
+    name: 'resolve',
+
+    async resolveId(source, importer) {
+      // Always exclude builtin modules
+      if (builtinModules.includes(source)) {
+        return false
+      }
+
+      const cwd = importer && dirname(importer)
+      if (cwd && PACKAGE_NAME_RE.test(source)) {
+        const id = await resolvePackage(source, { basedir: cwd })
+        return id
+      }
+      return null
+    },
+  }
+}
diff --git a/yarn.lock b/yarn.lock
index 8d43bfbd6..c24bfb3d5 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2,26 +2,135 @@
 # yarn lockfile v1
 
 
+"@rollup/plugin-commonjs@^11.1.0":
+  version "11.1.0"
+  resolved "https://registry.yarnpkg.com/@rollup/plugin-commonjs/-/plugin-commonjs-11.1.0.tgz#60636c7a722f54b41e419e1709df05c7234557ef"
+  integrity sha512-Ycr12N3ZPN96Fw2STurD21jMqzKwL9QuFhms3SD7KKRK7oaXUsBU9Zt0jL/rOPHiPYisI21/rXGO3jr9BnLHUA==
+  dependencies:
+    "@rollup/pluginutils" "^3.0.8"
+    commondir "^1.0.1"
+    estree-walker "^1.0.1"
+    glob "^7.1.2"
+    is-reference "^1.1.2"
+    magic-string "^0.25.2"
+    resolve "^1.11.0"
+
+"@rollup/pluginutils@^3.0.10", "@rollup/pluginutils@^3.0.8":
+  version "3.0.10"
+  resolved "https://registry.yarnpkg.com/@rollup/pluginutils/-/pluginutils-3.0.10.tgz#a659b9025920378494cd8f8c59fbf9b3a50d5f12"
+  integrity sha512-d44M7t+PjmMrASHbhgpSbVgtL6EFyX7J4mYxwQ/c5eoaE6N2VgCgEcWVzNnwycIloti+/MpwFr8qfw+nRw00sw==
+  dependencies:
+    "@types/estree" "0.0.39"
+    estree-walker "^1.0.1"
+    picomatch "^2.2.2"
+
+"@types/estree@0.0.39":
+  version "0.0.39"
+  resolved "https://registry.yarnpkg.com/@types/estree/-/estree-0.0.39.tgz#e177e699ee1b8c22d23174caaa7422644389509f"
+  integrity sha512-EYNwp3bU+98cpU4lAWYYL7Zz+2gryWH1qbdDTidVd6hkiR6weksdbMadyXKXNPEkQFhXM+hVO9ZygomHXp+AIw==
+
+"@types/node@*":
+  version "13.13.5"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-13.13.5.tgz#96ec3b0afafd64a4ccea9107b75bf8489f0e5765"
+  integrity sha512-3ySmiBYJPqgjiHA7oEaIo2Rzz0HrOZ7yrNO5HWyaE5q0lQ3BppDZ3N53Miz8bw2I7gh1/zir2MGVZBvpb1zq9g==
+
 "@types/node@^13.9.2":
   version "13.9.2"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-13.9.2.tgz#ace1880c03594cc3e80206d96847157d8e7fa349"
   integrity sha512-bnoqK579sAYrQbp73wwglccjJ4sfRdKU7WNEZ5FW4K2U6Kc0/eZ5kvXG0JKsEKFB50zrFmfFt52/cvBbZa7eXg==
 
+"@types/resolve@^1.17.0":
+  version "1.17.0"
+  resolved "https://registry.yarnpkg.com/@types/resolve/-/resolve-1.17.0.tgz#eb25b38e2682f641d33841df162e052d7364eaa8"
+  integrity sha512-CKOBcXAHvoGEjYsg6Bkc/kLPqTmtnUEGrWnJJC6LNnk+D36uc1GAHcNnwK2g58x/JWjGlqGfIao9rsJk7LePWw==
+  dependencies:
+    "@types/node" "*"
+
+balanced-match@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
+  integrity sha1-ibTRmasr7kneFk6gK4nORi1xt2c=
+
+brace-expansion@^1.1.7:
+  version "1.1.11"
+  resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-1.1.11.tgz#3c7fcbf529d87226f3d2f52b966ff5271eb441dd"
+  integrity sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==
+  dependencies:
+    balanced-match "^1.0.0"
+    concat-map "0.0.1"
+
 cac@^6.5.8:
   version "6.5.8"
   resolved "https://registry.yarnpkg.com/cac/-/cac-6.5.8.tgz#b15d183ee478226f846888be74612ac080533667"
   integrity sha512-jLv2+ps4T2HRVR1k4UlQZoAFvliAhf5LVR0yjPjIaIr/Cw99p/I7CXIEkXtw5q+AkYk4NCFJcF5ErmELSyrZnw==
 
+colorette@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/colorette/-/colorette-1.1.0.tgz#1f943e5a357fac10b4e0f5aaef3b14cdc1af6ec7"
+  integrity sha512-6S062WDQUXi6hOfkO/sBPVwE5ASXY4G2+b4atvhJfSsuUUhIaUKlkjLe9692Ipyt5/a+IPF5aVTu3V5gvXq5cg==
+
+commondir@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/commondir/-/commondir-1.0.1.tgz#ddd800da0c66127393cca5950ea968a3aaf1253b"
+  integrity sha1-3dgA2gxmEnOTzKWVDqloo6rxJTs=
+
+concat-map@0.0.1:
+  version "0.0.1"
+  resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
+  integrity sha1-2Klr13/Wjfd5OnMDajug1UBdR3s=
+
 esbuild@^0.2.9:
   version "0.2.10"
   resolved "https://registry.yarnpkg.com/esbuild/-/esbuild-0.2.10.tgz#28ad1d39a032ae4dfe78b5eb344ed5062e70a4c2"
   integrity sha512-Drg5gA+NF+Dc1Qd2J/Jjvpmtv2PQqeyEjIP6ipY6bz1sUOHKK3/R+v7oitr7/M8rNrI9PrUYPSR5M6hb2edoog==
 
+estree-walker@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/estree-walker/-/estree-walker-1.0.1.tgz#31bc5d612c96b704106b477e6dd5d8aa138cb700"
+  integrity sha512-1fMXF3YP4pZZVozF8j/ZLfvnR8NSIljt56UhbZ5PeeDmmGHpgpdwQt7ITlGvYaQukCvuBRMLEiKiYC+oeIg4cg==
+
+fs.realpath@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
+  integrity sha1-FQStJSMVjKpA20onh8sBQRmU6k8=
+
 fsevents@~2.1.2:
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/fsevents/-/fsevents-2.1.2.tgz#4c0a1fb34bc68e543b4b82a9ec392bfbda840805"
   integrity sha512-R4wDiBwZ0KzpgOWetKDug1FZcYhqYnUYKtfZYt4mD5SBz76q0KR4Q9o7GIPamsVPGmW3EYPPJ0dOOjvx32ldZA==
 
+glob@^7.1.2:
+  version "7.1.6"
+  resolved "https://registry.yarnpkg.com/glob/-/glob-7.1.6.tgz#141f33b81a7c2492e125594307480c46679278a6"
+  integrity sha512-LwaxwyZ72Lk7vZINtNNrywX0ZuLyStrdDtabefZKAY5ZGJhVtgdznluResxNmPitE0SAO+O26sWTHeKSI2wMBA==
+  dependencies:
+    fs.realpath "^1.0.0"
+    inflight "^1.0.4"
+    inherits "2"
+    minimatch "^3.0.4"
+    once "^1.3.0"
+    path-is-absolute "^1.0.0"
+
+inflight@^1.0.4:
+  version "1.0.6"
+  resolved "https://registry.yarnpkg.com/inflight/-/inflight-1.0.6.tgz#49bd6331d7d02d0c09bc910a1075ba8165b56df9"
+  integrity sha1-Sb1jMdfQLQwJvJEKEHW6gWW1bfk=
+  dependencies:
+    once "^1.3.0"
+    wrappy "1"
+
+inherits@2:
+  version "2.0.4"
+  resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.4.tgz#0fa2c64f932917c3433a0ded55363aae37416b7c"
+  integrity sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==
+
+is-reference@^1.1.2:
+  version "1.1.4"
+  resolved "https://registry.yarnpkg.com/is-reference/-/is-reference-1.1.4.tgz#3f95849886ddb70256a3e6d062b1a68c13c51427"
+  integrity sha512-uJA/CDPO3Tao3GTrxYn6AwkM4nUPJiGGYu5+cB8qbC7WGFlrKZbiRo7SFKxUAEpFUfiHofWCXBUNhvYJMh+6zw==
+  dependencies:
+    "@types/estree" "0.0.39"
+
 magic-string@^0.22.4:
   version "0.22.5"
   resolved "https://registry.yarnpkg.com/magic-string/-/magic-string-0.22.5.tgz#8e9cf5afddf44385c1da5bc2a6a0dbd10b03657e"
@@ -29,11 +138,55 @@ magic-string@^0.22.4:
   dependencies:
     vlq "^0.2.2"
 
-rollup-plugin-esbuild@^1.2.0:
-  version "1.2.0"
-  resolved "https://registry.yarnpkg.com/rollup-plugin-esbuild/-/rollup-plugin-esbuild-1.2.0.tgz#370f13b3031bb6f968be4f8bafee7ddc3bf22080"
-  integrity sha512-1wFivEfmSW2zYEi+TTYn+l6w9iSSrYc2ioFoD+jTzL4SycqmtiiB1RlyFVFVCGA3oNxddNdKZggBYNm1NQPNCg==
+magic-string@^0.25.2:
+  version "0.25.7"
+  resolved "https://registry.yarnpkg.com/magic-string/-/magic-string-0.25.7.tgz#3f497d6fd34c669c6798dcb821f2ef31f5445051"
+  integrity sha512-4CrMT5DOHTDk4HYDlzmwu4FVCcIYI8gauveasrdCu2IKIFOJ3f0v/8MDGJCDL9oD2ppz/Av1b0Nj345H9M+XIA==
+  dependencies:
+    sourcemap-codec "^1.4.4"
+
+minimatch@^3.0.4:
+  version "3.0.4"
+  resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.4.tgz#5166e286457f03306064be5497e8dbb0c3d32083"
+  integrity sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==
+  dependencies:
+    brace-expansion "^1.1.7"
+
+once@^1.3.0:
+  version "1.4.0"
+  resolved "https://registry.yarnpkg.com/once/-/once-1.4.0.tgz#583b1aa775961d4b113ac17d9c50baef9dd76bd1"
+  integrity sha1-WDsap3WWHUsROsF9nFC6753Xa9E=
+  dependencies:
+    wrappy "1"
+
+path-is-absolute@^1.0.0:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/path-is-absolute/-/path-is-absolute-1.0.1.tgz#174b9268735534ffbc7ace6bf53a5a9e1b5c5f5f"
+  integrity sha1-F0uSaHNVNP+8es5r9TpanhtcX18=
+
+path-parse@^1.0.6:
+  version "1.0.6"
+  resolved "https://registry.yarnpkg.com/path-parse/-/path-parse-1.0.6.tgz#d62dbb5679405d72c4737ec58600e9ddcf06d24c"
+  integrity sha512-GSmOT2EbHrINBf9SR7CDELwlJ8AENk3Qn7OikK4nFYAu3Ote2+JYNVvkpAEQm3/TLNEJFD/xZJjzyxg3KBWOzw==
+
+picomatch@^2.2.2:
+  version "2.2.2"
+  resolved "https://registry.yarnpkg.com/picomatch/-/picomatch-2.2.2.tgz#21f333e9b6b8eaff02468f5146ea406d345f4dad"
+  integrity sha512-q0M/9eZHzmr0AulXyPwNfZjtwZ/RBZlbN3K3CErVrk50T2ASYI7Bye0EvekFY3IP1Nt2DHu0re+V2ZHIpMkuWg==
+
+resolve@^1.11.0, resolve@^1.17.0:
+  version "1.17.0"
+  resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.17.0.tgz#b25941b54968231cc2d1bb76a79cb7f2c0bf8444"
+  integrity sha512-ic+7JYiV8Vi2yzQGFWOkiZD5Z9z7O2Zhm9XMaTxdJExKasieFCr+yXZ/WmXsckHiKl12ar0y6XiXDx3m4RHn1w==
   dependencies:
+    path-parse "^1.0.6"
+
+rollup-plugin-esbuild@^1.3.1:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/rollup-plugin-esbuild/-/rollup-plugin-esbuild-1.3.1.tgz#f87c25bec618c940a44ecc95ce52f61eb544b494"
+  integrity sha512-wsb0fXwBsNThSzgdJuom7UtZD1hMoe+/K4YHNz+XGxp4I8SXW+bFEgUvpl6snnFOnee8p+ozxK3BDR1z/rmjRg==
+  dependencies:
+    "@rollup/pluginutils" "^3.0.10"
     esbuild "^0.2.9"
 
 rollup-plugin-hashbang@^2.2.2:
@@ -50,6 +203,11 @@ rollup@^2.8.2:
   optionalDependencies:
     fsevents "~2.1.2"
 
+sourcemap-codec@^1.4.4:
+  version "1.4.8"
+  resolved "https://registry.yarnpkg.com/sourcemap-codec/-/sourcemap-codec-1.4.8.tgz#ea804bd94857402e6992d05a38ef1ae35a9ab4c4"
+  integrity sha512-9NykojV5Uih4lgo5So5dtw+f0JgJX30KCNI8gwhz2J9A15wD0Ml6tjHKwf6fTSa6fAdVBdZeNOs9eJ71qCk8vA==
+
 typescript@^3.8.3:
   version "3.8.3"
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.8.3.tgz#409eb8544ea0335711205869ec458ab109ee1061"
@@ -59,3 +217,8 @@ vlq@^0.2.2:
   version "0.2.3"
   resolved "https://registry.yarnpkg.com/vlq/-/vlq-0.2.3.tgz#8f3e4328cf63b1540c0d67e1b2778386f8975b26"
   integrity sha512-DRibZL6DsNhIgYQ+wNdWDL2SL3bKPlVrRiBqV5yuMm++op8W4kGFtaQfCs4KEJn0wBZcHVHJ3eoywX8983k1ow==
+
+wrappy@1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"
+  integrity sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=