diff --git a/packages/webpack-cli/lib/groups/ConfigGroup.js b/packages/webpack-cli/lib/groups/ConfigGroup.js
index d98a6183154..beac89662e8 100644
--- a/packages/webpack-cli/lib/groups/ConfigGroup.js
+++ b/packages/webpack-cli/lib/groups/ConfigGroup.js
@@ -167,17 +167,7 @@ const finalize = async (moduleObj, args) => {
             // `Promise` may return `Function`
             if (typeof rawConfig === 'function') {
                 // when config is a function, pass the env from args to the config function
-                let envs;
-
-                if (Array.isArray(env)) {
-                    envs = env.reduce((envObject, envOption) => {
-                        envObject[envOption] = true;
-
-                        return envObject;
-                    }, {});
-                }
-
-                rawConfig = await rawConfig(envs, args);
+                rawConfig = await rawConfig(env, args);
             }
 
             return rawConfig;
diff --git a/packages/webpack-cli/lib/utils/arg-parser.js b/packages/webpack-cli/lib/utils/arg-parser.js
index dc2fbe82729..e60e1833b02 100644
--- a/packages/webpack-cli/lib/utils/arg-parser.js
+++ b/packages/webpack-cli/lib/utils/arg-parser.js
@@ -92,6 +92,28 @@ const argParser = (options, args, argsOnly = false, name = '') => {
                 // a multiple argument parsing function
                 const multiArg = (value, previous = []) => previous.concat([value]);
                 parserInstance.option(flagsWithType, option.description, multiArg, option.defaultValue).action(() => {});
+            } else if (option.multipleType) {
+                // for options which accept multiple types like env
+                // so you can do `--env platform=staging --env production`
+                // { platform: "staging", production: true }
+                const multiArg = (value, previous = {}) => {
+                    // this ensures we're only splitting by the first `=`
+                    const [allKeys, val] = value.split(/=(.+)/, 2);
+                    const splitKeys = allKeys.split(/\.(?!$)/);
+                    let prevRef = previous;
+                    splitKeys.forEach((someKey, index) => {
+                        if (!prevRef[someKey]) prevRef[someKey] = {};
+                        if ('string' === typeof prevRef[someKey]) {
+                            prevRef[someKey] = {};
+                        }
+                        if (index === splitKeys.length - 1) {
+                            prevRef[someKey] = val || true;
+                        }
+                        prevRef = prevRef[someKey];
+                    });
+                    return previous;
+                };
+                parserInstance.option(flagsWithType, option.description, multiArg, option.defaultValue).action(() => {});
             } else {
                 // Prevent default behavior for standalone options
                 parserInstance.option(flagsWithType, option.description, option.defaultValue).action(() => {});
diff --git a/packages/webpack-cli/lib/utils/cli-flags.js b/packages/webpack-cli/lib/utils/cli-flags.js
index 0f5f508169a..807d94c0677 100644
--- a/packages/webpack-cli/lib/utils/cli-flags.js
+++ b/packages/webpack-cli/lib/utils/cli-flags.js
@@ -205,7 +205,7 @@ const core = [
         name: 'env',
         usage: '--env',
         type: String,
-        multiple: true,
+        multipleType: true,
         description: 'Environment passed to the configuration when it is a function',
     },
     {
diff --git a/test/config/type/function-with-env/function-with-env.test.js b/test/config/type/function-with-env/function-with-env.test.js
index fae211de366..bbb878377ee 100644
--- a/test/config/type/function-with-env/function-with-env.test.js
+++ b/test/config/type/function-with-env/function-with-env.test.js
@@ -4,6 +4,13 @@ const { resolve } = require('path');
 const { run } = require('../../../utils/test-utils');
 
 describe('function configuration', () => {
+    it('should throw when env is not supplied', () => {
+        const { stderr, stdout, exitCode } = run(__dirname, ['--env'], false);
+        expect(stdout).toBeFalsy();
+        expect(stderr).toBeTruthy();
+        expect(stderr).toContain(`option '--env <value>' argument missing`);
+        expect(exitCode).toEqual(1);
+    });
     it('is able to understand a configuration file as a function', () => {
         const { stderr, stdout } = run(__dirname, ['--env', 'isProd']);
         expect(stderr).toBeFalsy();
@@ -18,6 +25,62 @@ describe('function configuration', () => {
         // Should generate the appropriate files
         expect(existsSync(resolve(__dirname, './bin/dev.js'))).toBeTruthy();
     });
+    it('Supports passing string in env', () => {
+        const { stderr, stdout } = run(__dirname, [
+            '--env',
+            'environment=production',
+            '--env',
+            'app.title=Luffy',
+            '-c',
+            'webpack.env.config.js',
+        ]);
+        expect(stderr).toBeFalsy();
+        expect(stdout).toBeTruthy();
+        // Should generate the appropriate files
+        expect(existsSync(resolve(__dirname, './bin/Luffy.js'))).toBeTruthy();
+    });
+    it('Supports long nested values in env', () => {
+        const { stderr, stdout } = run(__dirname, [
+            '--env',
+            'file.name.is.this=Atsumu',
+            '--env',
+            'environment=production',
+            '-c',
+            'webpack.env.config.js',
+        ]);
+        expect(stderr).toBeFalsy();
+        expect(stdout).toBeTruthy();
+        // Should generate the appropriate files
+        expect(existsSync(resolve(__dirname, './bin/Atsumu.js'))).toBeTruthy();
+    });
+    it('Supports multiple equal in a string', () => {
+        const { stderr, stdout } = run(__dirname, [
+            '--env',
+            'file=name=is=Eren',
+            '--env',
+            'environment=multipleq',
+            '-c',
+            'webpack.env.config.js',
+        ]);
+        expect(stderr).toBeFalsy();
+        expect(stdout).toBeTruthy();
+        // Should generate the appropriate files
+        expect(existsSync(resolve(__dirname, './bin/name=is=Eren.js'))).toBeTruthy();
+    });
+    it('Supports dot at the end', () => {
+        const { stderr, stdout } = run(__dirname, ['--env', 'name.=Hisoka', '--env', 'environment=dot', '-c', 'webpack.env.config.js']);
+        expect(stderr).toBeFalsy();
+        expect(stdout).toBeTruthy();
+        // Should generate the appropriate files
+        expect(existsSync(resolve(__dirname, './bin/Hisoka.js'))).toBeTruthy();
+    });
+    it('Supports dot at the end', () => {
+        const { stderr, stdout } = run(__dirname, ['--env', 'name.', '--env', 'environment=dot', '-c', 'webpack.env.config.js']);
+        expect(stderr).toBeFalsy();
+        expect(stdout).toBeTruthy();
+        // Should generate the appropriate files
+        expect(existsSync(resolve(__dirname, './bin/true.js'))).toBeTruthy();
+    });
     it('is able to understand multiple env flags', (done) => {
         const { stderr, stdout } = run(__dirname, ['--env', 'isDev', '--env', 'verboseStats', '--env', 'envMessage']);
         expect(stderr).toBeFalsy();
diff --git a/test/config/type/function-with-env/webpack.env.config.js b/test/config/type/function-with-env/webpack.env.config.js
new file mode 100644
index 00000000000..b131cf9866d
--- /dev/null
+++ b/test/config/type/function-with-env/webpack.env.config.js
@@ -0,0 +1,32 @@
+module.exports = (env) => {
+    const { environment, app, file } = env;
+    const customName = file && file.name && file.name.is && file.name.is.this;
+    const appTitle = app && app.title;
+    if (environment === 'production') {
+        return {
+            entry: './a.js',
+            output: {
+                filename: `${customName ? customName : appTitle}.js`,
+            },
+        };
+    }
+    if (environment === 'multipleq') {
+        const { file } = env;
+        return {
+            entry: './a.js',
+            output: {
+                filename: `${file}.js`,
+            },
+        };
+    }
+    if (environment === 'dot') {
+        const file = env['name.'];
+        return {
+            entry: './a.js',
+            output: {
+                filename: `${file}.js`,
+            },
+        };
+    }
+    return {};
+};
diff --git a/test/config/type/promise-function/promise-function.test.js b/test/config/type/promise-function/promise-function.test.js
index 220e908bae5..ad5f372201e 100644
--- a/test/config/type/promise-function/promise-function.test.js
+++ b/test/config/type/promise-function/promise-function.test.js
@@ -6,8 +6,6 @@ const { run } = require('../../../utils/test-utils');
 describe('promise function', () => {
     it('is able to understand a configuration file as a promise', (done) => {
         const { stdout, stderr } = run(__dirname, ['-c', './webpack.config.js'], false);
-        console.log(stdout);
-        console.log(stderr);
         expect(stdout).toBeTruthy();
         expect(stderr).toBeFalsy();
         stat(resolve(__dirname, './binary/promise.js'), (err, stats) => {