diff --git a/.changeset/dirty-snakes-sip.md b/.changeset/dirty-snakes-sip.md
new file mode 100644
index 000000000..a99dcf054
--- /dev/null
+++ b/.changeset/dirty-snakes-sip.md
@@ -0,0 +1,5 @@
+---
+'@segment/analytics-core': patch
+---
+
+Tighten isPlainObject type guard
diff --git a/packages/browser/package.json b/packages/browser/package.json
index 015645423..e7cdb42e6 100644
--- a/packages/browser/package.json
+++ b/packages/browser/package.json
@@ -24,7 +24,7 @@
   ],
   "sideEffects": false,
   "scripts": {
-    ".": "yarn run -T turbo run --filter=@segment/analytics-next",
+    ".": "yarn run -T turbo run --filter=@segment/analytics-next...",
     "build-prep": "sh scripts/build-prep.sh",
     "version": "yarn run build-prep && git add src/generated/version.ts",
     "umd": "webpack",
diff --git a/packages/core/src/validation/helpers.ts b/packages/core/src/validation/helpers.ts
index b1d6de641..511b03a64 100644
--- a/packages/core/src/validation/helpers.ts
+++ b/packages/core/src/validation/helpers.ts
@@ -16,7 +16,7 @@ export function exists<T>(val: unknown): val is NonNullable<T> {
 
 export function isPlainObject(
   obj: unknown
-): obj is Record<string | symbol | number, any> {
+): obj is Record<string | symbol | number, unknown> {
   return (
     Object.prototype.toString.call(obj).slice(8, -1).toLowerCase() === 'object'
   )