diff --git a/package.json b/package.json
index e962049..2fb3318 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "processout.js",
-  "version": "1.9.15",
+  "version": "1.9.16",
   "description": "ProcessOut.js is a JavaScript library for ProcessOut's payment processing API.",
   "scripts": {
     "build:processout": "tsc -p src/processout && uglifyjs --compress --keep-fnames --ie8 dist/processout.js -o dist/processout.js",
diff --git a/src/processout/processout.ts b/src/processout/processout.ts
index 0174d7e..897dbeb 100644
--- a/src/processout/processout.ts
+++ b/src/processout/processout.ts
@@ -239,7 +239,7 @@ module ProcessOut {
           return
         }
 
-        if (/^https?:\/\/.*\.processout\.((com)|(ninja)|(dev))\//.test(event.filename)) {
+        if (isProcessOutScriptError(event)) {
           setTimeout(() => {
             this.telemetryClient.reportError({
               host: window && window.location ? window.location.host : "",
diff --git a/src/processout/telemetry.ts b/src/processout/telemetry.ts
index 4e43790..a65b992 100644
--- a/src/processout/telemetry.ts
+++ b/src/processout/telemetry.ts
@@ -24,6 +24,18 @@ module ProcessOut {
 
   type LogLevel = "error" | "warn" | "info" | "debug"
 
+  const processOutScriptURL =
+    /^https?:\/\/[^/]*\.processout\.(com|ninja|dev)\/processout\.js([?#]|$)/
+
+  /**
+   * Whether a window error event was thrown by processout.js itself. Some
+   * browsers attribute errors from their injected scripts to the page URL, so
+   * matching any ProcessOut-hosted file reports errors that aren't ours.
+   */
+  export function isProcessOutScriptError(event: ErrorEvent): boolean {
+    return !!event && !!event.error && processOutScriptURL.test(event.filename || "")
+  }
+
   export class TelemetryClient {
     protected processOutInstance: ProcessOut
 
diff --git a/test/processout/telemetry.test.ts b/test/processout/telemetry.test.ts
new file mode 100644
index 0000000..ed26844
--- /dev/null
+++ b/test/processout/telemetry.test.ts
@@ -0,0 +1,41 @@
+import { describe, expect, it } from "vitest"
+import { loadTelemetry } from "../support/loadNamespace"
+
+const { isProcessOutScriptError } = loadTelemetry()
+
+function errorEvent(filename: string, error: unknown = new Error("boom")) {
+  return { filename, error } as unknown as ErrorEvent
+}
+
+describe("isProcessOutScriptError", () => {
+  it("accepts errors thrown by processout.js", () => {
+    expect(isProcessOutScriptError(errorEvent("https://js.processout.com/processout.js"))).toBe(
+      true,
+    )
+    expect(
+      isProcessOutScriptError(errorEvent("https://js.processout.ninja/processout.js?v=1")),
+    ).toBe(true)
+  })
+
+  it("rejects errors attributed to a processout-hosted page", () => {
+    const page = "https://checkout.processout.com/some/page"
+    expect(isProcessOutScriptError(errorEvent(page))).toBe(false)
+  })
+
+  it("rejects other scripts on processout or lookalike hosts", () => {
+    expect(isProcessOutScriptError(errorEvent("https://js.processout.com/modal.js"))).toBe(false)
+    expect(isProcessOutScriptError(errorEvent("https://js.processout.com/processout.json"))).toBe(
+      false,
+    )
+    expect(
+      isProcessOutScriptError(errorEvent("https://processout.com.evil.io/processout.js")),
+    ).toBe(false)
+    expect(isProcessOutScriptError(errorEvent("https://merchant.example/app.js"))).toBe(false)
+  })
+
+  it("rejects events without an error object", () => {
+    expect(
+      isProcessOutScriptError(errorEvent("https://js.processout.com/processout.js", null)),
+    ).toBe(false)
+  })
+})
diff --git a/test/support/loadNamespace.ts b/test/support/loadNamespace.ts
index 4f8021b..b1ef93d 100644
--- a/test/support/loadNamespace.ts
+++ b/test/support/loadNamespace.ts
@@ -156,3 +156,14 @@ export function loadDynamicCheckout(): DynamicCheckoutNamespace {
 
   return { namespace: moduleShim.exports, dispatchedEvents }
 }
+
+/**
+ * Load `src/processout/telemetry.ts` and return its `ProcessOut` namespace.
+ */
+export function loadTelemetry(): Record<string, any> {
+  const js = compile("src/processout/telemetry.ts")
+  const moduleShim = { exports: {} as Record<string, any> }
+  const run = new Function("module", "exports", `${js}\nmodule.exports = ProcessOut;`)
+  run(moduleShim, moduleShim.exports)
+  return moduleShim.exports
+}