diff --git a/tools/release-packages/src/publish-dirs.ts b/tools/release-packages/src/publish-dirs.ts
index 2777f88cc..e7e97b26f 100644
--- a/tools/release-packages/src/publish-dirs.ts
+++ b/tools/release-packages/src/publish-dirs.ts
@@ -66,16 +66,20 @@ interface PackageExports {
   [key: string]: PackageExports | string | undefined
 }
 
-interface PublishPackageJSON extends Record<string, unknown> {
+interface PublishPackageJSON extends PackageJSON {
   exports?: PackageExports
   imports?: PackageExports
 }
 
+function isPackageExports(value: unknown): value is PackageExports {
+  return typeof value === 'object' && value !== null && !Array.isArray(value)
+}
+
 function removeUnpublishedConditions(value: PackageExports | undefined): void {
   if (!value) return
   delete value.bun
   for (const child of Object.values(value)) {
-    if (typeof child === 'object' && child) removeUnpublishedConditions(child)
+    if (isPackageExports(child)) removeUnpublishedConditions(child)
   }
 }
 
diff --git a/tools/release-packages/src/tarballs.ts b/tools/release-packages/src/tarballs.ts
index cfcca7ab1..2c8d2db44 100644
--- a/tools/release-packages/src/tarballs.ts
+++ b/tools/release-packages/src/tarballs.ts
@@ -5,8 +5,14 @@ import { promisify } from 'node:util'
 
 const execFileAsync = promisify(execFile)
 
+type PackageExports = {
+  [key: string]: PackageExports | string | null | undefined
+}
+
 type PackageJSON = {
   bin?: Record<string, string> | string
+  exports?: PackageExports
+  imports?: PackageExports
   name: string
 }
 
@@ -22,7 +28,7 @@ function packageExportTargets(value: unknown): string[] {
   return Object.values(value).flatMap(packageExportTargets)
 }
 
-export function packageExportTargetPaths(packageJSON: { exports?: unknown }): string[] {
+export function packageExportTargetPaths(packageJSON: Pick<PackageJSON, 'exports'>): string[] {
   return packageExportTargets(packageJSON.exports)
 }
 
@@ -52,7 +58,7 @@ export async function validateTarballBinTargets(tarballPath: string): Promise<vo
 
 export async function validateTarballExportTargets(tarballPath: string): Promise<void> {
   const entries = await tarballEntries(tarballPath)
-  const packageJSON = (await tarballPackageJSON(tarballPath)) as PackageJSON & { exports?: unknown }
+  const packageJSON = await tarballPackageJSON(tarballPath)
 
   for (const target of packageExportTargetPaths(packageJSON)) {
     if (!target.startsWith('./')) continue