diff --git a/build.config.ts b/build.config.ts
index d99a4d3..53d3ba5 100644
--- a/build.config.ts
+++ b/build.config.ts
@@ -4,14 +4,38 @@
  * @see https://github.com/flex-development/mkbuild
  */
 
-import { defineBuildConfig, type Config } from '@flex-development/mkbuild'
-import { constant, define } from '@flex-development/tutils'
+import { unassert } from '@flex-development/estree-util-unassert'
+import {
+  defineBuildConfig,
+  type Config,
+  type OutputMetadata
+} from '@flex-development/mkbuild'
+import pathe from '@flex-development/pathe'
+import {
+  DOT,
+  constant,
+  define,
+  entries,
+  get,
+  overwrite
+} from '@flex-development/tutils'
 import { ok } from 'devlop'
-import type { BuildResult, PluginBuild } from 'esbuild'
+import { fromJs } from 'esast-util-from-js'
+import type { BuildResult, Metafile, OutputFile, PluginBuild } from 'esbuild'
+import type { Program } from 'estree'
+import { attachComments } from 'estree-util-attach-comments'
+import { toJs } from 'estree-util-to-js'
+import { visit } from 'estree-util-visit'
 import util from 'node:util'
 import pkg from './package.json' assert { type: 'json' }
 import tsconfig from './tsconfig.build.json' assert { type: 'json' }
 
+declare module 'estree' {
+  interface BaseNode {
+    position?: import('unist').Position | undefined
+  }
+}
+
 /**
  * Build configuration options.
  *
@@ -23,23 +47,9 @@ const config: Config = defineBuildConfig({
     {
       dts: 'only'
     },
-    {
-      dts: 'only',
-      outdir: 'dist/dev'
-    },
     {
       dts: false,
-      ignore: ['interfaces'],
-      outdir: 'dist/dev',
-      sourcemap: true,
-      sourcesContent: false
-    },
-    {
-      dts: false,
-      ignore: ['interfaces'],
-      plugins: [],
-      sourcemap: true,
-      sourcesContent: false
+      ignore: ['interfaces', 'types']
     }
   ],
   plugins: [
@@ -59,7 +69,7 @@ const config: Config = defineBuildConfig({
        */
       setup(build: PluginBuild): void {
         /**
-         * Regular expression used to fix module specifier.
+         * Regular expression used to fix module specifiers.
          *
          * @const {RegExp} regex
          */
@@ -80,6 +90,160 @@ const config: Config = defineBuildConfig({
           }
         })
       }
+    },
+    {
+      /**
+       * Plugin name.
+       */
+      name: unassert.name,
+
+      /**
+       * Remove assertions.
+       *
+       * @this {void}
+       *
+       * @param {PluginBuild} build - esbuild plugin api
+       * @return {void} Nothing
+       */
+      setup(build: PluginBuild): void {
+        const {
+          absWorkingDir: cwd = process.cwd(),
+          format,
+          outdir = DOT
+        } = build.initialOptions
+
+        /**
+         * Directory to store development output files.
+         *
+         * @const {string} devdir
+         */
+        const devdir: string = pathe.join(outdir, 'dev')
+
+        return void build.onEnd((result: BuildResult): void => {
+          ok(result.metafile, 'expected metafile')
+          ok(result.outputFiles, 'expected output files')
+
+          /**
+           * Output file filter.
+           *
+           * @const {RegExp} filter
+           */
+          const filter: RegExp = /\.[cm]{0,1}js$/
+
+          /**
+           * Development output file metadata.
+           *
+           * @const {Metafile['outputs']} outputs
+           */
+          const outputs: Metafile['outputs'] = {}
+
+          /**
+           * Development output files.
+           *
+           * @const {OutputFile[]} outputs
+           */
+          const outputFiles: OutputFile[] = []
+
+          // get development output file metadata
+          for (const [path, output] of entries(result.metafile.outputs)) {
+            if (filter.test(path)) {
+              define(outputs, path.replace(outdir, devdir), { value: output })
+            }
+          }
+
+          // handle output files
+          for (const output of result.outputFiles) {
+            if (filter.test(output.path)) {
+              /**
+               * JavaScript syntax tree.
+               *
+               * @const {Program} tree
+               */
+              const tree: Program = fromJs(output.text, {
+                module: format !== 'iife'
+              })
+
+              // attach comments
+              visit(tree, node => void (node.loc = node.position))
+              attachComments(tree, tree.comments)
+              delete tree.comments
+
+              // remove assertions
+              unassert(tree)
+
+              /**
+               * Relative path to output file.
+               *
+               * @const {string} outfile
+               */
+              const outfile: string = output.path.replace(cwd + pathe.sep, '')
+
+              /**
+               * Path to development output file.
+               *
+               * @const {string} devpath
+               */
+              const devpath: string = pathe.resolve(
+                cwd,
+                devdir,
+                outfile.replace(outdir + pathe.sep, '')
+              )
+
+              /**
+               * Output file text.
+               *
+               * @const {string} text
+               */
+              const text: string = toJs(tree).value
+
+              /**
+               * Output file contents.
+               *
+               * @const {Uint8Array} contents
+               */
+              const contents: Uint8Array = new util.TextEncoder().encode(text)
+
+              /**
+               * Output file metadata.
+               *
+               * @const {OutputMetadata} metadata
+               */
+              const metadata: OutputMetadata = get(
+                result.metafile.outputs,
+                outfile
+              )
+
+              // assert output file metadata
+              ok(metadata, 'expected output file metadata')
+
+              // add development output file
+              outputFiles.push(
+                define({ contents: output.contents, path: devpath }, 'text', {
+                  get: constant(output.text)
+                })
+              )
+
+              // update output file
+              define(output, 'text', { get: constant(text) })
+              output.contents = new util.TextEncoder().encode(output.text)
+
+              // update output file metadata
+              define(result.metafile.outputs, outfile, {
+                value: overwrite(metadata, {
+                  bytes: contents.byteLength,
+                  imports: metadata.imports.filter(({ path }) => {
+                    return !unassert.MODULES_REGEX.test(path)
+                  })
+                })
+              })
+            }
+          }
+
+          // update output files and metadata
+          result.outputFiles = [...outputFiles, ...result.outputFiles]
+          result.metafile.outputs = { ...outputs, ...result.metafile.outputs }
+        })
+      }
     }
   ],
   target: [
diff --git a/package.json b/package.json
index f1ac077..2b8ea83 100644
--- a/package.json
+++ b/package.json
@@ -32,13 +32,12 @@
   ],
   "exports": {
     ".": {
+      "types": "./dist/index.d.mts",
       "development": "./dist/dev/index.mjs",
       "default": "./dist/index.mjs"
     },
     "./package.json": "./package.json"
   },
-  "module": "./dist/index.mjs",
-  "types": "./dist/index.d.mts",
   "scripts": {
     "build": "node --loader=./loader.mjs --enable-source-maps ./build",
     "check:ci": "yarn dedupe --check && yarn check:format && yarn check:lint && yarn check:spelling && yarn typecheck && yarn test:cov && yarn pack && yarn check:types:build && attw package.tgz && yarn clean:pack",
diff --git a/src/unassert.ts b/src/unassert.ts
index a4bade6..577ec19 100644
--- a/src/unassert.ts
+++ b/src/unassert.ts
@@ -47,4 +47,10 @@ function unassert(this: void, tree: Program, options?: Nilable<Options>): void {
   })
 }
 
+/**
+ * @property {RegExp} MODULES_REGEX - Default regular expression used to match
+ * assertion module ids
+ */
+unassert.MODULES_REGEX = MODULES_REGEX
+
 export default unassert