diff --git a/packages/packemon/src/Package.ts b/packages/packemon/src/Package.ts
index 7c98839fb..e478e68c5 100644
--- a/packages/packemon/src/Package.ts
+++ b/packages/packemon/src/Package.ts
@@ -438,25 +438,25 @@ export class Package {
 		this.artifacts.forEach((artifact) => {
 			// Build files
 			if (artifact instanceof CodeArtifact) {
+				const mainEntryName = artifact.inputs.index ? 'index' : Object.keys(artifact.inputs)[0];
+
 				buildCount += artifact.builds.length;
 
 				// Generate `main`, `module`, and `browser` fields
-				if (artifact.inputs.index) {
-					if (!mainEntry || artifact.platform === 'node') {
-						mainEntry = artifact.findEntryPoint(['lib', 'cjs', 'mjs', 'esm'], 'index');
-					}
-
-					if (!moduleEntry) {
-						moduleEntry = artifact.findEntryPoint(['esm'], 'index');
-					}
-
-					// Only include when we share a lib with another platform
-					if (!browserEntry && artifact.platform === 'browser') {
-						browserEntry = artifact.findEntryPoint(
-							artifact.sharedLib ? ['lib', 'umd'] : ['umd'],
-							'index',
-						);
-					}
+				if (!mainEntry || (artifact.platform === 'node' && mainEntryName === 'index')) {
+					mainEntry = artifact.findEntryPoint(['lib', 'cjs', 'mjs', 'esm'], mainEntryName);
+				}
+
+				if (!moduleEntry || (artifact.platform === 'browser' && mainEntryName === 'index')) {
+					moduleEntry = artifact.findEntryPoint(['esm'], mainEntryName);
+				}
+
+				// Only include when we share a lib with another platform
+				if (!browserEntry && artifact.platform === 'browser') {
+					browserEntry = artifact.findEntryPoint(
+						artifact.sharedLib ? ['lib', 'umd'] : ['umd'],
+						mainEntryName,
+					);
 				}
 
 				// Generate `bin` field
@@ -471,7 +471,11 @@ export class Package {
 
 			// Type declarations
 			if (artifact instanceof TypesArtifact) {
-				this.packageJson.types = artifact.findEntryPoint('index');
+				const mainEntryName = artifact.builds.some((build) => build.outputName === 'index')
+					? 'index'
+					: artifact.builds[0].outputName;
+
+				this.packageJson.types = artifact.findEntryPoint(mainEntryName);
 			}
 		});
 
diff --git a/packages/packemon/tests/Package.test.ts b/packages/packemon/tests/Package.test.ts
index 74c29dfcb..83d6c3df2 100644
--- a/packages/packemon/tests/Package.test.ts
+++ b/packages/packemon/tests/Package.test.ts
@@ -320,14 +320,14 @@ describe('Package', () => {
 					);
 				});
 
-				it('doesnt add "main" if output name is not "index"', async () => {
+				it('adds "main" if output name is not "index"', async () => {
 					const a = createCodeArtifact([{ format: 'lib' }]);
 					a.inputs = { server: 'src/index.ts' };
 					pkg.addArtifact(a);
 
 					await pkg.build({}, config);
 
-					expect(pkg.packageJson.main).toBeUndefined();
+					expect(pkg.packageJson.main).toBe('./lib/server.js');
 				});
 
 				it('adds "main" when using shared `lib` format', async () => {
diff --git a/packages/packemon/tests/__snapshots__/outputs.test.ts.snap b/packages/packemon/tests/__snapshots__/outputs.test.ts.snap
index a0780e34c..d93fc8794 100644
--- a/packages/packemon/tests/__snapshots__/outputs.test.ts.snap
+++ b/packages/packemon/tests/__snapshots__/outputs.test.ts.snap
@@ -192,10 +192,12 @@ exports[`Outputs (babel) artifacts builds all the artifacts with rollup 6`] = `
 Array [
   "package.json",
   Object {
+    "browser": "./umd/client.js",
     "dependencies": Object {
       "typescript": "*",
     },
     "main": "./lib/index.js",
+    "module": "./esm/client.js",
     "name": "project-rollup",
     "packemon": Object {
       "inputs": Object {
@@ -859,10 +861,12 @@ exports[`Outputs (swc) artifacts builds all the artifacts with rollup 6`] = `
 Array [
   "package.json",
   Object {
+    "browser": "./umd/client.js",
     "dependencies": Object {
       "typescript": "*",
     },
     "main": "./lib/index.js",
+    "module": "./esm/client.js",
     "name": "project-rollup",
     "packemon": Object {
       "inputs": Object {