diff --git a/package.json b/package.json
index 35b6eb4..06b33ac 100644
--- a/package.json
+++ b/package.json
@@ -30,6 +30,7 @@
     "chai": "^4.3.6",
     "copy-webpack-plugin": "^10.2.4",
     "css-loader": "^6.6.0",
+    "esmock": "^2.3.1",
     "license-check-and-add": "^4.0.5",
     "mini-css-extract-plugin": "^2.5.3",
     "mocha": "^10.1.0",
@@ -44,7 +45,7 @@
   "scripts": {
     "start": "node --experimental-fetch ./",
     "dev": "LOG_LEVEL=debug yarn run watch & yarn run build:static:dev",
-    "test": "yarn run standard:check && yarn run rome:check && mocha",
+    "test": "yarn run standard:check && yarn run rome:check && mocha --loader=esmock",
     "watch": "./node_modules/.bin/nodemon --config nodemon.json ./",
     "build": "yarn run build:server & yarn run build:static",
     "build:server": "ncc build ./src/index.js -o dist",
diff --git a/src/server/index.js b/src/server/index.js
index d35dbc3..eeef49c 100644
--- a/src/server/index.js
+++ b/src/server/index.js
@@ -32,12 +32,6 @@ import * as doipjs from 'doipjs'
 import { fetchWKD, fetchHKP, fetchSignature, fetchKeybase } from './keys.js'
 import libravatar from 'libravatar'
 
-const scheme = process.env.PROXY_SCHEME
-  ? process.env.PROXY_SCHEME
-  : process.env.SCHEME
-    ? process.env.SCHEME
-    : 'https'
-
 const generateWKDProfile = async (id) => {
   logger.debug('Generating a WKD profile',
     { component: 'wkd_profile_generator', action: 'start', profile_id: id })
@@ -52,7 +46,7 @@ const generateWKDProfile = async (id) => {
       keyData = processKeyData(keyData)
 
       const keyoxideData = {}
-      keyoxideData.url = `${scheme}://${process.env.DOMAIN}/wkd/${id}`
+      keyoxideData.url = `${getScheme()}://${process.env.DOMAIN}/wkd/${id}`
 
       logger.debug('Generating a WKD profile',
         { component: 'wkd_profile_generator', action: 'done', profile_id: id })
@@ -94,9 +88,9 @@ const generateHKPProfile = async (id, keyserverDomain) => {
 
       const keyoxideData = {}
       if (!keyserverDomain || keyserverDomain === 'keys.openpgp.org') {
-        keyoxideData.url = `${scheme}://${process.env.DOMAIN}/hkp/${id}`
+        keyoxideData.url = `${getScheme()}://${process.env.DOMAIN}/hkp/${id}`
       } else {
-        keyoxideData.url = `${scheme}://${process.env.DOMAIN}/hkp/${keyserverDomain}/${id}`
+        keyoxideData.url = `${getScheme()}://${process.env.DOMAIN}/hkp/${keyserverDomain}/${id}`
       }
 
       logger.debug('Generating a HKP profile',
@@ -202,7 +196,7 @@ const generateKeybaseProfile = async (username, fingerprint) => {
       keyData = processKeyData(keyData)
 
       const keyoxideData = {}
-      keyoxideData.url = `${scheme}://${process.env.DOMAIN}/keybase/${username}/${fingerprint}`
+      keyoxideData.url = `${getScheme()}://${process.env.DOMAIN}/keybase/${username}/${fingerprint}`
 
       logger.debug('Generating a Keybase profile',
         { component: 'keybase_profile_generator', action: 'done', username, fingerprint })
@@ -271,6 +265,14 @@ const computeExtraData = async (key, keyData) => {
   }
 }
 
+const getScheme = () => {
+  return process.env.PROXY_SCHEME
+    ? process.env.PROXY_SCHEME
+    : process.env.SCHEME
+      ? process.env.SCHEME
+      : 'https'
+}
+
 export { generateWKDProfile }
 export { generateHKPProfile }
 export { generateAutoProfile }
diff --git a/test/server.test.js b/test/server.test.js
index 42185f9..192d53f 100644
--- a/test/server.test.js
+++ b/test/server.test.js
@@ -1,6 +1,10 @@
 import 'chai/register-should.js'
+import esmock from 'esmock'
+
 import * as utils from '../src/server/utils.js'
 
+const _env = Object.assign({},process.env)
+
 describe('server', function () {
     describe('utils', function () {
         describe('computeWKDLocalPart()', function () {
@@ -26,4 +30,107 @@ describe('server', function () {
             })
         })
     })
+
+    // NOTE: This is necessarily brittle. If these tests fail
+    // in the future, start looking here for what new behaviour
+    // in the implementation is or isn't getting mocked
+    // appropriately.
+    describe('index', function () {
+
+        describe('generateHKPProfile()', function() {
+
+            let index;
+            let fingerprint;
+
+            this.beforeEach(async () => {
+
+                // Common arrangement pieces that don't change per test
+                fingerprint = '79895B2E0F87503F1DDE80B649765D7F0DDD9BD5'
+                process.env.DOMAIN = "keyoxide.org"
+
+                // mock the appropriate pieces of our dependencies so we
+                // can test just the `keyoxide.url` return value.
+                index = await esmock('../src/server/index.js', {
+                    '../src/server/keys.js': {
+                        fetchHKP: () => {
+                            return Promise.resolve({
+                                publicKey: {
+                                    getPrimaryUser: () => {
+                                        return {
+                                            user: {
+                                                userID: {
+                                                    email: "example@example.net"
+                                                }
+                                            }
+                                        }
+                                    }
+                                },
+                                fetchURL: 'example.com'
+                            })
+                        }
+                    },
+                    'doipjs': {
+                        keys: {
+                            process: () => {
+                                return { 
+                                    key: {},
+                                    'fingerprint': fingerprint,
+                                    users: [] 
+                                }
+                            }
+                        }
+                    },
+                    'libravatar': {
+                        get_avatar_url: () => {
+                            return "example.org/avatar.png"
+                        }
+                    }
+                })
+            })
+
+            this.afterEach(() => {
+                process.env = _env
+            })
+
+            it('should handle implicit scheme for keyoxide URL', async function () {
+
+                // Arrange
+                // no setting process.env.SCHEME
+
+                // Act
+                const local = await index.generateHKPProfile(fingerprint)
+
+                // Assert
+                local.keyoxide.url.should.equal(`https://keyoxide.org/hkp/${fingerprint}`)
+
+            })
+
+            it('should handle explicit http scheme for keyoxide URL', async function () {
+
+                // Arrange
+                process.env.SCHEME = "http"
+
+                // Act
+                const local = await index.generateHKPProfile(fingerprint)
+
+                // Assert
+                local.keyoxide.url.should.equal(`http://keyoxide.org/hkp/${fingerprint}`)
+
+            })
+
+            it('should handle explicit https scheme for keyoxide URL', async function () {
+
+                // Arrange
+                process.env.SCHEME = "https"
+
+                // Act
+                const local = await index.generateHKPProfile(fingerprint)
+
+                // Assert
+                local.keyoxide.url.should.equal(`https://keyoxide.org/hkp/${fingerprint}`)
+
+            })
+
+        })
+    })
 })
\ No newline at end of file
diff --git a/yarn.lock b/yarn.lock
index 19a39c0..3614114 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2204,6 +2204,11 @@ eslint@^8.13.0:
     strip-json-comments "^3.1.0"
     text-table "^0.2.0"
 
+esmock@^2.3.1:
+  version "2.3.1"
+  resolved "https://registry.yarnpkg.com/esmock/-/esmock-2.3.1.tgz#27a3afea73d7fb352f27c7ac04f66cfbd2c34316"
+  integrity sha512-ZxuxfhwGSlStiJFbw6Z+a70fB6SutTcUr0X8dhehx6aqiC5kgBvEYV4xNW94cKaD8gaqD7P00RjBH/pfao2CQA==
+
 espree@^9.4.0:
   version "9.4.1"
   resolved "https://registry.yarnpkg.com/espree/-/espree-9.4.1.tgz#51d6092615567a2c2cff7833445e37c28c0065bd"