diff --git a/src/builders/rollup/build.ts b/src/builders/rollup/build.ts
index 8b3d6f40..f7c49889 100644
--- a/src/builders/rollup/build.ts
+++ b/src/builders/rollup/build.ts
@@ -9,6 +9,7 @@ import { getRollupOptions } from "./config";
 import { getChunkFilename } from "./utils";
 import { rollupStub } from "./stub";
 import { rollupWatch } from "./watch";
+import { fixCJSExportTypePlugin } from "./plugins/cjs";
 
 export async function rollupBuild(ctx: BuildContext): Promise<void> {
   // Stub mode
@@ -81,7 +82,8 @@ export async function rollupBuild(ctx: BuildContext): Promise<void> {
       ...rollupOptions.plugins,
       dts(ctx.options.rollup.dts),
       removeShebangPlugin(),
-    ];
+      ctx.options.rollup.emitCJS && fixCJSExportTypePlugin(),
+    ].filter(Boolean);
 
     await ctx.hooks.callHook("rollup:dts:options", ctx, rollupOptions);
     const typesBuild = await rollup(rollupOptions);
diff --git a/src/builders/rollup/plugins/cjs.ts b/src/builders/rollup/plugins/cjs.ts
index 2bba6d0e..5edfa5bd 100644
--- a/src/builders/rollup/plugins/cjs.ts
+++ b/src/builders/rollup/plugins/cjs.ts
@@ -14,6 +14,29 @@ export function cjsPlugin(_opts?: any): Plugin {
   } as Plugin;
 }
 
+// Ported from https://github.com/egoist/tsup/blob/cd03e1e00ec2bd6676ae1837cbc7e618ab6a2362/src/rollup.ts#L92-L109
+export function fixCJSExportTypePlugin(): Plugin {
+  return {
+    name: "unbuild-fix-cjs-export-type",
+    renderChunk(code, info, opts) {
+      if (
+        info.type !== "chunk" ||
+        !info.fileName.endsWith(".d.cts") ||
+        !info.isEntry ||
+        info.exports?.length !== 1 ||
+        info.exports[0] !== "default"
+      ) {
+        return;
+      }
+
+      return code.replace(
+        /(?<=(?<=[;}]|^)\s*export\s*){\s*([\w$]+)\s*as\s+default\s*}/,
+        `= $1`,
+      );
+    },
+  } as Plugin;
+}
+
 const CJSyntaxRe = /__filename|__dirname|require\(|require\.resolve\(/;
 
 const CJSShim = `