diff --git a/__tests__/distributors/adopt-installer.test.ts b/__tests__/distributors/adopt-installer.test.ts
index 5442d3f6..55649255 100644
--- a/__tests__/distributors/adopt-installer.test.ts
+++ b/__tests__/distributors/adopt-installer.test.ts
@@ -170,7 +170,8 @@ describe('getAvailableVersions', () => {
   });
 
   it('stops pagination after 1000 pages as a safeguard', async () => {
-    const nextPageUrl = 'https://example.com/releases?page=2';
+    const nextPageUrl =
+      'https://api.adoptopenjdk.net/v3/assets/version/%5B1.0,100.0%5D?page=2&page_size=20';
     spyHttpClient.mockReturnValue({
       statusCode: 200,
       headers: {link: `<${nextPageUrl}>; rel="next"`},
diff --git a/__tests__/distributors/semeru-installer.test.ts b/__tests__/distributors/semeru-installer.test.ts
index ffef9530..03b08b72 100644
--- a/__tests__/distributors/semeru-installer.test.ts
+++ b/__tests__/distributors/semeru-installer.test.ts
@@ -113,7 +113,8 @@ describe('getAvailableVersions', () => {
   });
 
   it('stops pagination after 1000 pages as a safeguard', async () => {
-    const nextPageUrl = 'https://example.com/releases?page=2';
+    const nextPageUrl =
+      'https://api.adoptopenjdk.net/v3/assets/version/%5B1.0,100.0%5D?page=2&page_size=20';
     spyHttpClient.mockReturnValue({
       statusCode: 200,
       headers: {link: `<${nextPageUrl}>; rel="next"`},
diff --git a/__tests__/distributors/temurin-installer.test.ts b/__tests__/distributors/temurin-installer.test.ts
index 49a52a7d..161a2d08 100644
--- a/__tests__/distributors/temurin-installer.test.ts
+++ b/__tests__/distributors/temurin-installer.test.ts
@@ -127,7 +127,8 @@ describe('getAvailableVersions', () => {
   });
 
   it('stops pagination after 1000 pages as a safeguard', async () => {
-    const nextPageUrl = 'https://example.com/releases?page=2';
+    const nextPageUrl =
+      'https://api.adoptium.net/v3/assets/version/%5B1.0,100.0%5D?page=2&page_size=20';
     spyHttpClient.mockReturnValue({
       statusCode: 200,
       headers: {link: `<${nextPageUrl}>; rel="next"`},
diff --git a/__tests__/util.test.ts b/__tests__/util.test.ts
index d3746cc7..2df3bb94 100644
--- a/__tests__/util.test.ts
+++ b/__tests__/util.test.ts
@@ -108,6 +108,10 @@ describe('getNextPageUrlFromLinkHeader', () => {
       'https://api.adoptium.net/v3/versions?page=3'
     ],
     [{link: '<https://example.com/last?page=5>; rel="last"'}, null],
+    [
+      {link: '<https://example.com/page?p=2>; rel="nextsomething"'},
+      null
+    ],
     [undefined, null]
   ])('returns %s -> %s', (headers, expected) => {
     expect(getNextPageUrlFromLinkHeader(headers)).toBe(expected);
@@ -147,6 +151,15 @@ describe('validatePaginationUrl', () => {
       validatePaginationUrl('not-a-url', 'https://api.adoptium.net')
     ).toBe(false);
   });
+
+  it('accepts URL with explicit default port', () => {
+    expect(
+      validatePaginationUrl(
+        'https://api.adoptium.net:443/v3/assets?page=2',
+        'https://api.adoptium.net'
+      )
+    ).toBe(true);
+  });
 });
 
 describe('getVersionFromFileContent', () => {
diff --git a/src/util.ts b/src/util.ts
index 3b507214..5fe84c52 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -227,7 +227,9 @@ export function getNextPageUrlFromLinkHeader(
     if (!urlMatch) continue;
 
     const params = linkValue.slice(urlMatch[0].length);
-    if (/;\s*rel="?next"?/i.test(params)) {
+    // Use word boundary to match "next" as a standalone relation type
+    // RFC 8288 allows space-separated relation types like rel="next prev"
+    if (/;\s*rel="?[^"]*\bnext\b/i.test(params)) {
       return urlMatch[1];
     }
   }
@@ -242,9 +244,7 @@ export function validatePaginationUrl(
   try {
     const parsed = new URL(url);
     const allowed = new URL(allowedOrigin);
-    return (
-      parsed.protocol === allowed.protocol && parsed.host === allowed.host
-    );
+    return parsed.origin === allowed.origin;
   } catch {
     return false;
   }