diff --git a/packages/catalog-model/package.json b/packages/catalog-model/package.json
index 60208aeebb..64f49e34e6 100644
--- a/packages/catalog-model/package.json
+++ b/packages/catalog-model/package.json
@@ -1,9 +1,7 @@
 {
   "name": "@backstage/catalog-model",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.cjs.js",
-  "module": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/packages/cli/config/jest.js b/packages/cli/config/jest.js
index 4567d8c593..ad24976ad0 100644
--- a/packages/cli/config/jest.js
+++ b/packages/cli/config/jest.js
@@ -25,32 +25,13 @@ async function getConfig() {
     return require(path.resolve('jest.config.ts'));
   }
 
-  const moduleNameMapper = {
-    '\\.(css|less|scss|sss|styl)$': require.resolve('jest-css-modules'),
-  };
-
-  // Only point to src/ if we're not in CI, there we just build packages first anyway
-  if (!process.env.CI) {
-    const LernaProject = require('@lerna/project');
-    const project = new LernaProject(path.resolve('.'));
-    const packages = await project.getPackages();
-
-    // To avoid having to build all deps inside the monorepo before running tests,
-    // we point directory to src/ where applicable.
-    // For example, @backstage/core = <repo-root>/packages/core/src/index.ts is added to moduleNameMapper
-    for (const pkg of packages) {
-      const mainSrc = pkg.get('main:src');
-      if (mainSrc) {
-        moduleNameMapper[`^${pkg.name}$`] = path.resolve(pkg.location, mainSrc);
-      }
-    }
-  }
-
   const options = {
     rootDir: path.resolve('src'),
     coverageDirectory: path.resolve('coverage'),
     collectCoverageFrom: ['**/*.{js,jsx,ts,tsx}', '!**/*.d.ts'],
-    moduleNameMapper,
+    moduleNameMapper: {
+      '\\.(css|less|scss|sss|styl)$': require.resolve('jest-css-modules'),
+    },
 
     // We build .esm.js files with plugin:build, so to be able to load these in tests they need to be transformed
     // TODO: jest is working on module support, it's possible that we can remove this in the future
diff --git a/packages/cli/src/lib/bundler/config.ts b/packages/cli/src/lib/bundler/config.ts
index d5fb674ec1..6fe8092e50 100644
--- a/packages/cli/src/lib/bundler/config.ts
+++ b/packages/cli/src/lib/bundler/config.ts
@@ -109,7 +109,7 @@ export function createConfig(
     entry: [require.resolve('react-hot-loader/patch'), paths.targetEntry],
     resolve: {
       extensions: ['.ts', '.tsx', '.mjs', '.js', '.jsx'],
-      mainFields: ['main:src', 'browser', 'module', 'main'],
+      mainFields: ['browser', 'module', 'main'],
       plugins: [
         new ModuleScopePlugin(
           [paths.targetSrc, paths.targetDev],
@@ -183,7 +183,7 @@ export function createBackendConfig(
     ],
     resolve: {
       extensions: ['.ts', '.tsx', '.mjs', '.js', '.jsx'],
-      mainFields: ['main:src', 'browser', 'module', 'main'],
+      mainFields: ['browser', 'module', 'main'],
       modules: [paths.targetNodeModules, paths.rootNodeModules],
       plugins: [
         new ModuleScopePlugin(
diff --git a/packages/cli/src/lib/tasks.ts b/packages/cli/src/lib/tasks.ts
index 481241a869..b6e2bebb41 100644
--- a/packages/cli/src/lib/tasks.ts
+++ b/packages/cli/src/lib/tasks.ts
@@ -171,9 +171,7 @@ export async function installWithLocalDeps(dir: string) {
   });
 
   // This takes care of pointing all the installed packages from this repo to
-  // dist instead of the local src.
-  // For example node_modules/@backstage/core/packages.json is rewritten to point
-  // types to dist/index.d.ts and the main:src field is removed.
+  // dist instead of the local src, using the field overrides in publishConfig.
   // Without this we get type checking errors in the e2e test
   if (process.env.BACKSTAGE_E2E_CLI_TEST) {
     Task.section('Patching local dependencies for e2e tests');
@@ -192,7 +190,6 @@ export async function installWithLocalDeps(dir: string) {
           const depJson = await fs.readJson(depJsonPath);
 
           // We want dist to be used for e2e tests
-          delete depJson['main:src'];
           for (const key of Object.keys(depJson.publishConfig)) {
             if (key !== 'access') {
               depJson[key] = depJson.publishConfig[key];
diff --git a/packages/cli/templates/default-app/plugins/welcome/package.json.hbs b/packages/cli/templates/default-app/plugins/welcome/package.json.hbs
index c590b68324..d916677d33 100644
--- a/packages/cli/templates/default-app/plugins/welcome/package.json.hbs
+++ b/packages/cli/templates/default-app/plugins/welcome/package.json.hbs
@@ -1,8 +1,7 @@
 {
   "name": "plugin-welcome",
   "version": "0.0.0",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "private": true,
   "publishConfig": {
diff --git a/packages/cli/templates/default-plugin/package.json.hbs b/packages/cli/templates/default-plugin/package.json.hbs
index c92795cc04..b04da6b793 100644
--- a/packages/cli/templates/default-plugin/package.json.hbs
+++ b/packages/cli/templates/default-plugin/package.json.hbs
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-{{id}}",
   "version": "{{version}}",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": true,
diff --git a/packages/core-api/package.json b/packages/core-api/package.json
index 2659a23ef6..4e3c8ef139 100644
--- a/packages/core-api/package.json
+++ b/packages/core-api/package.json
@@ -18,8 +18,7 @@
     "backstage"
   ],
   "license": "Apache-2.0",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "scripts": {
     "build": "backstage-cli build --outputs types,esm",
diff --git a/packages/core/package.json b/packages/core/package.json
index 01b7ed124d..f84181f626 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -18,8 +18,7 @@
     "backstage"
   ],
   "license": "Apache-2.0",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "scripts": {
     "build": "backstage-cli build --outputs types,esm",
diff --git a/packages/dev-utils/package.json b/packages/dev-utils/package.json
index af1f813148..425d507b17 100644
--- a/packages/dev-utils/package.json
+++ b/packages/dev-utils/package.json
@@ -18,8 +18,7 @@
     "backstage"
   ],
   "license": "Apache-2.0",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "scripts": {
     "build": "backstage-cli build --outputs types,esm",
diff --git a/packages/storybook/.storybook/main.js b/packages/storybook/.storybook/main.js
index b8f78f5d2c..2ee58a8c4f 100644
--- a/packages/storybook/.storybook/main.js
+++ b/packages/storybook/.storybook/main.js
@@ -16,7 +16,7 @@ module.exports = {
     const coreSrc = path.resolve(__dirname, '../../core/src');
 
     // Mirror config in packages/cli/src/lib/bundler
-    config.resolve.mainFields = ['main:src', 'browser', 'module', 'main'];
+    config.resolve.mainFields = ['browser', 'module', 'main'];
 
     // Remove the default babel-loader for js files, we're using sucrase instead
     const [jsLoader] = config.module.rules.splice(0, 1);
diff --git a/packages/test-utils-core/package.json b/packages/test-utils-core/package.json
index a71a23c844..3b18ff4c1c 100644
--- a/packages/test-utils-core/package.json
+++ b/packages/test-utils-core/package.json
@@ -18,8 +18,7 @@
     "backstage"
   ],
   "license": "Apache-2.0",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "scripts": {
     "build": "backstage-cli build --outputs types,esm",
diff --git a/packages/test-utils/package.json b/packages/test-utils/package.json
index 7c5a229aba..c0752f87ac 100644
--- a/packages/test-utils/package.json
+++ b/packages/test-utils/package.json
@@ -18,8 +18,7 @@
     "backstage"
   ],
   "license": "Apache-2.0",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "scripts": {
     "build": "backstage-cli build --outputs types,esm",
diff --git a/packages/theme/package.json b/packages/theme/package.json
index 72a10eb1f3..1c6c096a8f 100644
--- a/packages/theme/package.json
+++ b/packages/theme/package.json
@@ -18,8 +18,7 @@
     "backstage"
   ],
   "license": "Apache-2.0",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "scripts": {
     "build": "backstage-cli build --outputs types,esm",
diff --git a/plugins/catalog/package.json b/plugins/catalog/package.json
index 54d5737adb..ddffb1f932 100644
--- a/plugins/catalog/package.json
+++ b/plugins/catalog/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-catalog",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/circleci/package.json b/plugins/circleci/package.json
index 0104c5cc7b..f59d93106a 100644
--- a/plugins/circleci/package.json
+++ b/plugins/circleci/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-circleci",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/explore/package.json b/plugins/explore/package.json
index ad3205f514..74076e9fbb 100644
--- a/plugins/explore/package.json
+++ b/plugins/explore/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-explore",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/gitops-profiles/package.json b/plugins/gitops-profiles/package.json
index c9dca36e08..ee4406be4c 100644
--- a/plugins/gitops-profiles/package.json
+++ b/plugins/gitops-profiles/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-gitops-profiles",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/graphiql/package.json b/plugins/graphiql/package.json
index 49293acbfb..9d4a797c82 100644
--- a/plugins/graphiql/package.json
+++ b/plugins/graphiql/package.json
@@ -18,8 +18,7 @@
     "backstage"
   ],
   "license": "Apache-2.0",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "scripts": {
     "build": "backstage-cli plugin:build",
diff --git a/plugins/lighthouse/package.json b/plugins/lighthouse/package.json
index a3c65d05ea..c96013a814 100644
--- a/plugins/lighthouse/package.json
+++ b/plugins/lighthouse/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-lighthouse",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/register-component/package.json b/plugins/register-component/package.json
index d999ab1dcc..e4c84e448d 100644
--- a/plugins/register-component/package.json
+++ b/plugins/register-component/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-register-component",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/scaffolder/package.json b/plugins/scaffolder/package.json
index 84132a42f9..5c6859cf57 100644
--- a/plugins/scaffolder/package.json
+++ b/plugins/scaffolder/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-scaffolder",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/sentry/package.json b/plugins/sentry/package.json
index 7a8197ab87..80435cf38a 100644
--- a/plugins/sentry/package.json
+++ b/plugins/sentry/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-sentry",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/tech-radar/package.json b/plugins/tech-radar/package.json
index e0146e8a72..16a36dba5d 100644
--- a/plugins/tech-radar/package.json
+++ b/plugins/tech-radar/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-tech-radar",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "private": false,
diff --git a/plugins/welcome/package.json b/plugins/welcome/package.json
index 6780f7df98..deed9012da 100644
--- a/plugins/welcome/package.json
+++ b/plugins/welcome/package.json
@@ -1,8 +1,7 @@
 {
   "name": "@backstage/plugin-welcome",
   "version": "0.1.1-alpha.9",
-  "main": "dist/index.esm.js",
-  "main:src": "src/index.ts",
+  "main": "src/index.ts",
   "types": "src/index.ts",
   "private": false,
   "license": "Apache-2.0",