diff --git a/ts/package-lock.json b/ts/package-lock.json
index 713a62f4f..00d637262 100644
--- a/ts/package-lock.json
+++ b/ts/package-lock.json
@@ -9,6 +9,7 @@
       "version": "1.0.0",
       "license": "Apache-2.0",
       "dependencies": {
+        "ip-regex": "^5.0.0",
         "memoizee": "^0.4.17",
         "psl": "^1.15.0",
         "structured-headers": "^2.0.1",
@@ -2173,6 +2174,17 @@
         "node": ">=10.13.0"
       }
     },
+    "node_modules/ip-regex": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/ip-regex/-/ip-regex-5.0.0.tgz",
+      "integrity": "sha512-fOCG6lhoKKakwv+C6KdsOnGvgXnmgfmp0myi3bcNwj3qfwPAxRKWEuFhvEFF7ceYIz6+1jRZ+yguLFAmUNPEfw==",
+      "engines": {
+        "node": "^12.20.0 || ^14.13.1 || >=16.0.0"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/is-arguments": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/is-arguments/-/is-arguments-1.1.1.tgz",
diff --git a/ts/package.json b/ts/package.json
index 71bb40785..862d45b20 100644
--- a/ts/package.json
+++ b/ts/package.json
@@ -16,6 +16,7 @@
   "author": "",
   "license": "Apache-2.0",
   "dependencies": {
+    "ip-regex": "^5.0.0",
     "memoizee": "^0.4.17",
     "psl": "^1.15.0",
     "structured-headers": "^2.0.1",
diff --git a/ts/src/header-validator/source.test.ts b/ts/src/header-validator/source.test.ts
index bc0144d0c..330da4298 100644
--- a/ts/src/header-validator/source.test.ts
+++ b/ts/src/header-validator/source.test.ts
@@ -28,7 +28,7 @@ const testCases: TestCase[] = [
       "aggregation_keys": {"a": "0xf"},
       "debug_key": "1",
       "debug_reporting": true,
-      "destination": "https://a.test",
+      "destination": ["https://a.test", "https://1.2.3.4"],
       "destination_limit_priority": "1",
       "event_report_window": "3601",
       "expiry": "86400",
@@ -61,7 +61,7 @@ const testCases: TestCase[] = [
       aggregationKeys: new Map([['a', 15n]]),
       debugKey: 1n,
       debugReporting: true,
-      destination: new Set(['https://a.test']),
+      destination: new Set(['https://a.test', 'https://1.2.3.4']),
       destinationLimitPriority: 1n,
       eventLevelEpsilon: 14,
       expiry: 86400,
@@ -116,7 +116,7 @@ const testCases: TestCase[] = [
   },
   {
     name: 'destination-url-components',
-    input: `{"destination": ["https://a.test/b?c=d#e", "https://x.Y.test", "https://sub.A.test/z"]}`,
+    input: `{"destination": ["https://a.test/b?c=d#e", "https://x.Y.test", "https://sub.A.test/z", "https://1.2.3.4/5"]}`,
     expectedWarnings: [
       {
         path: ['destination', 0],
@@ -134,6 +134,10 @@ const testCases: TestCase[] = [
         path: ['destination', 2],
         msg: 'duplicate value https://a.test',
       },
+      {
+        msg: 'URL components other than site (https://1.2.3.4) will be ignored',
+        path: ['destination', 3],
+      },
     ],
   },
 
diff --git a/ts/src/header-validator/validate.ts b/ts/src/header-validator/validate.ts
index d728e86d3..1359eba01 100644
--- a/ts/src/header-validator/validate.ts
+++ b/ts/src/header-validator/validate.ts
@@ -1,3 +1,4 @@
+import ipRegex from 'ip-regex'
 import * as psl from 'psl'
 import { Context, PathComponent } from './context'
 import { Maybe } from './maybe'
@@ -376,6 +377,9 @@ export function suitableOrigin(s: string, ctx: Context): Maybe<string> {
 
 export function suitableSite(s: string, ctx: Context): Maybe<string> {
   return suitableScope(s, ctx, 'site', (u) => {
+    if (ipRegex({ exact: true }).test(u.hostname)) {
+      return `${u.protocol}//${u.hostname}`
+    }
     let site = psl.get(u.hostname)
     if (site === null) {
       ctx.warning(