diff --git a/src/ids-host.test.ts b/src/ids-host.test.ts
index 639b560..4c5e95c 100644
--- a/src/ids-host.test.ts
+++ b/src/ids-host.test.ts
@@ -1,7 +1,6 @@
 import {
   IdsHost,
   discoverServicesStub,
-  mungeDiagnosticEndpoint,
   orderRecordsByPriorityWeight,
   recordToUrl,
   weightedRandom,
@@ -145,60 +144,6 @@ describe("getDiagnosticsUrl", () => {
   }
 });
 
-describe("mungeDiagnosticEndpoint", () => {
-  type TestCase = {
-    description: string;
-    inputUrl: string;
-    defaultHost: string;
-    effectiveHost: string;
-    expectedUrl: string;
-  };
-
-  const testCases: TestCase[] = [
-    {
-      description:
-        "The input URL is taken as the literal value if the IDS host isn't overridden",
-      inputUrl: "https://foo.com/bar",
-      defaultHost: "https://default",
-      effectiveHost: "https://default",
-      expectedUrl: "https://foo.com/bar",
-    },
-    {
-      description:
-        "The input URL is taken as the literal value if the input URL's origin is pointed elsewhere",
-      inputUrl: "https://foo.com/bar",
-      defaultHost: "https://default",
-      effectiveHost: "https://someOtherHost",
-      expectedUrl: "https://foo.com/bar",
-    },
-    {
-      description:
-        "The overridden IDS host is used as the base of the diagnostic endpoint, with the inputUrl smushed on top of it",
-      inputUrl: "https://default/bar",
-      defaultHost: "https://default",
-      effectiveHost: "ftp://user:password@someOtherHost:1234",
-      expectedUrl: "ftp://user:password@someOtherHost:1234/bar",
-    },
-  ];
-
-  for (const {
-    description,
-    inputUrl,
-    defaultHost,
-    effectiveHost,
-    expectedUrl,
-  } of testCases) {
-    test(description, async () => {
-      const ret = await mungeDiagnosticEndpoint(
-        new URL(inputUrl),
-        new URL(defaultHost),
-        new URL(effectiveHost),
-      );
-      expect(ret).toStrictEqual(new URL(expectedUrl));
-    });
-  }
-});
-
 describe("recordToUrl", () => {
   test("a valid record", () => {
     expect(
diff --git a/src/ids-host.ts b/src/ids-host.ts
index 068ca7c..3e8e784 100644
--- a/src/ids-host.ts
+++ b/src/ids-host.ts
@@ -127,27 +127,6 @@ export class IdsHost {
   }
 }
 
-export function mungeDiagnosticEndpoint(
-  inputUrl: URL,
-  defaultIdsHost: URL,
-  selectedIdsHost: URL,
-): URL {
-  if (defaultIdsHost === selectedIdsHost) {
-    return inputUrl;
-  }
-
-  if (inputUrl.origin !== defaultIdsHost.origin) {
-    return inputUrl;
-  }
-
-  inputUrl.protocol = selectedIdsHost.protocol;
-  inputUrl.host = selectedIdsHost.host;
-  inputUrl.username = selectedIdsHost.username;
-  inputUrl.password = selectedIdsHost.password;
-
-  return inputUrl;
-}
-
 export function recordToUrl(record: SrvRecord): URL | undefined {
   const urlStr = `https://${record.name}:${record.port}`;
   try {