diff --git a/src/routes/stats/npm/-utils.ts b/src/routes/stats/npm/-utils.ts
index 1f31d27e0..1603e22f9 100644
--- a/src/routes/stats/npm/-utils.ts
+++ b/src/routes/stats/npm/-utils.ts
@@ -1,13 +1,8 @@
 import * as v from 'valibot'
 import { MAX_NPM_STATS_GROUPS } from '~/utils/npm-stats-limits'
 
-// Re-export shared types from chart utils
-export {
-  binTypeSchema,
-  type BinType,
-  binningOptions,
-  getBinFunction,
-} from '~/utils/chart'
+// Re-export shared types and schema without importing chart utilities.
+export { binTypeSchema, type BinType } from '~/components/npm-stats/shared'
 export {
   chartTypeSchema,
   type ChartType,
diff --git a/tests/chart-route-validation.test.ts b/tests/chart-route-validation.test.ts
new file mode 100644
index 000000000..927049730
--- /dev/null
+++ b/tests/chart-route-validation.test.ts
@@ -0,0 +1,27 @@
+/// <reference types="node" />
+
+import assert from 'node:assert/strict'
+import test from 'node:test'
+import { Route } from '../src/routes/stats/npm/$packages'
+
+const schema = Route.options.validateSearch
+assert.ok(schema && typeof schema === 'object' && '~standard' in schema)
+const standardSchema = schema['~standard']
+
+test('npm comparison route preserves binType search validation', async () => {
+  const defaultResult = await standardSchema.validate({})
+  assert.equal(defaultResult.issues, undefined)
+  assert.equal(defaultResult.value.binType, 'weekly')
+
+  for (const binType of ['yearly', 'monthly', 'weekly', 'daily']) {
+    const result = await standardSchema.validate({ binType })
+    assert.equal(result.issues, undefined)
+    assert.equal(result.value.binType, binType)
+  }
+})
+
+test('npm comparison route defaults invalid binType search values', async () => {
+  const result = await standardSchema.validate({ binType: 'hourly' })
+  assert.equal(result.issues, undefined)
+  assert.equal(result.value.binType, 'weekly')
+})