diff --git a/src/controllers/issueDetailsController.js b/src/controllers/issueDetailsController.js
index ed3661fa..7409145a 100644
--- a/src/controllers/issueDetailsController.js
+++ b/src/controllers/issueDetailsController.js
@@ -11,7 +11,7 @@ import { fetchOne } from '../middleware/middleware.builders.js'
 
 const validateParams = validateQueryParams({
   schema: v.object({
-    pageNumber: v.optional(v.pipe(v.string(), v.transform(parseInt), v.minValue(1)), '1')
+    pageNumber: v.optional(v.pipe(v.string(), v.transform(s => parseInt(s, 10)), v.number(), v.integer(), v.minValue(1)), '1')
   })
 })
 
diff --git a/src/controllers/resultsController.js b/src/controllers/resultsController.js
index 1775e015..6bb10011 100644
--- a/src/controllers/resultsController.js
+++ b/src/controllers/resultsController.js
@@ -555,7 +555,7 @@ export function getFileNameOrUrlAndCheckedTime (req, res, next) {
 
 const validateParams = validateQueryParams({
   schema: v.object({
-    pageNumber: v.optional(v.pipe(v.string(), v.transform(parseInt), v.minValue(1)), '1')
+    pageNumber: v.optional(v.pipe(v.string(), v.transform(s => parseInt(s, 10)), v.number(), v.integer(), v.minValue(1)), '1')
   })
 })
 
diff --git a/src/middleware/dataset-failed-expectation-entry.middleware.js b/src/middleware/dataset-failed-expectation-entry.middleware.js
index 73023917..57960725 100644
--- a/src/middleware/dataset-failed-expectation-entry.middleware.js
+++ b/src/middleware/dataset-failed-expectation-entry.middleware.js
@@ -41,7 +41,7 @@ const subPath = (organisation, dataset) => {
 export const validateExpectationParams = validateQueryParams({
   schema: v.object({
     expectation: ExpectationPathParams,
-    pageNumber: v.optional(v.pipe(v.string(), v.transform(s => parseInt(s, 10)), v.minValue(1)), '1')
+    pageNumber: v.optional(v.pipe(v.string(), v.transform(s => parseInt(s, 10)), v.number(), v.integer(), v.minValue(1)), '1')
   })
 })
 
diff --git a/src/middleware/dataview.middleware.js b/src/middleware/dataview.middleware.js
index 2a520de5..26554586 100644
--- a/src/middleware/dataview.middleware.js
+++ b/src/middleware/dataview.middleware.js
@@ -32,7 +32,7 @@ import { splitByLeading } from '../utils/table.js'
 export const dataviewQueryParams = v.object({
   lpa: v.string(),
   dataset: v.string(),
-  pageNumber: v.optional(v.pipe(v.string(), v.transform(s => parseInt(s, 10)), v.minValue(1)), '1'),
+  pageNumber: v.optional(v.pipe(v.string(), v.transform(s => parseInt(s, 10)), v.number(), v.integer(), v.minValue(1)), '1'),
   resourceId: v.optional(v.string())
 })
 
diff --git a/src/middleware/entryIssueDetails.middleware.js b/src/middleware/entryIssueDetails.middleware.js
index e3e90b8e..06d202a8 100644
--- a/src/middleware/entryIssueDetails.middleware.js
+++ b/src/middleware/entryIssueDetails.middleware.js
@@ -9,7 +9,7 @@ export const IssueDetailsQueryParams = v.object({
   dataset: v.string(),
   issue_type: v.string(),
   issue_field: v.string(),
-  pageNumber: v.optional(v.pipe(v.string(), v.transform(s => parseInt(s, 10)), v.minValue(1)), '1'),
+  pageNumber: v.optional(v.pipe(v.string(), v.transform(s => parseInt(s, 10)), v.number(), v.integer(), v.minValue(1)), '1'),
   resourceId: v.optional(v.string())
 })
 
diff --git a/test/unit/middleware/dataviewQueryParams.test.js b/test/unit/middleware/dataviewQueryParams.test.js
new file mode 100644
index 00000000..d4720953
--- /dev/null
+++ b/test/unit/middleware/dataviewQueryParams.test.js
@@ -0,0 +1,24 @@
+import { describe, it, expect } from 'vitest'
+import * as v from 'valibot'
+import { dataviewQueryParams } from '../../../src/middleware/dataview.middleware.js'
+
+// Regression: a non-numeric :pageNumber segment (e.g. /data/abc) used to parse
+// to NaN, slip past v.minValue(1), and crash later in getSetDataRange. The
+// schema now includes v.integer(), so invalid page numbers are rejected here.
+describe('dataviewQueryParams pageNumber', () => {
+  const base = { lpa: 'x', dataset: 'y' }
+
+  it('defaults to 1 when absent', () => {
+    expect(v.parse(dataviewQueryParams, base).pageNumber).toBe(1)
+  })
+
+  it('coerces a valid numeric string to a number', () => {
+    expect(v.parse(dataviewQueryParams, { ...base, pageNumber: '3' }).pageNumber).toBe(3)
+  })
+
+  // 'abc'/'' -> NaN; '0'/'-1' -> below the minimum. All must be rejected here
+  // rather than crashing downstream. (Note '2.5' parses to 2 and is valid.)
+  it.each(['abc', '', '0', '-1'])('rejects invalid pageNumber %j', (pageNumber) => {
+    expect(() => v.parse(dataviewQueryParams, { ...base, pageNumber })).toThrow()
+  })
+})