diff --git a/index.js b/index.js
index 246a81e..c380f2d 100644
--- a/index.js
+++ b/index.js
@@ -19,6 +19,7 @@ const fs = require('fs');
 const os = require('os');
 const path = require('path');
 const wd = require('wd');
+const which = require('which');
 const _ = require('lodash');
 
 const {installWebDrivers} = require('webdriver-installer');
@@ -41,6 +42,18 @@ const PLATFORM_MAP = {
   'linux': 'Linux',
 };
 
+function mergeOptions(base, custom) {
+  // _.mergeWith modifies the first argument, so clone the base structure first.
+  const output = _.cloneDeep(base);
+  return _.mergeWith(output, custom,
+      // Concatenate arrays instead of overwriting them.
+      (objValue, srcValue) => {
+        if (Array.isArray(objValue)) {
+          return objValue.concat(srcValue);
+        }
+      });
+}
+
 // Subclasses must define these static members:
 //  - BROWSER_NAME: browser name as presented to WebDriver
 //  - LAUNCHER_NAME: launcher name as presented to Karma
@@ -68,14 +81,9 @@ const LocalWebDriverBase = function(baseBrowserDecorator, args, logger) {
 
   log.debug('config:', JSON.stringify(config));
 
-  const extraSpecs = _.mergeWith(
+  const extraSpecs = mergeOptions(
       this.constructor.EXTRA_WEBDRIVER_SPECS,
-      args.config,
-      (objValue, srcValue) => {
-        if (Array.isArray(objValue)) {
-          return objValue.concat(srcValue);
-        }
-      });
+      args.config);
   log.debug('extraSpecs:', extraSpecs);
 
   // These names ("browser" and "spec") are needed for compatibility with
@@ -288,23 +296,35 @@ const LocalWebDriverChromeHeadless = generateSubclass(
 
 // TODO: Add Chrome on android?
 
+// If a binary is found with the name "microsoft-edge" in the PATH, specify
+// that explicitly.  This works around the following edgedriver bug:
+// https://github.com/MicrosoftEdge/EdgeWebDriver/issues/102#issuecomment-1710724173
+const edgeOptions = {};
+const edgeBinary = which.sync('microsoft-edge');
+if (edgeBinary) {
+  edgeOptions['ms:edgeOptions'] = {
+    binary: edgeBinary,
+  };
+}
+
 const LocalWebDriverEdge = generateSubclass(
     'MSEdge', 'MSEdge',
     'msedgedriver',
-    (port) => ['--port=' + port]);
+    (port) => ['--port=' + port],
+    edgeOptions);
 
 const LocalWebDriverEdgeHeadless = generateSubclass(
     'MSEdge', 'MSEdgeHeadless',
     'msedgedriver',
     (port) => ['--port=' + port],
-    {
+    mergeOptions(edgeOptions, {
       'ms:edgeOptions': {
         args: [
           '--headless',
           '--disable-gpu',
         ],
       },
-    });
+    }));
 
 const LocalWebDriverFirefox = generateSubclass(
     'Firefox', 'Firefox',
diff --git a/package-lock.json b/package-lock.json
index 3d09840..e8fb56f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,8 +10,9 @@
       "license": "Apache-2.0",
       "dependencies": {
         "lodash": "^4.17.21",
+        "node-which": "^1.0.0",
         "wd": "^1.14.0",
-        "webdriver-installer": "^1.1.8"
+        "webdriver-installer": "^1.1.9"
       },
       "peerDependencies": {
         "karma": "^6.2.0"
@@ -927,20 +928,6 @@
       "resolved": "https://registry.npmjs.org/fs.realpath/-/fs.realpath-1.0.0.tgz",
       "integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8="
     },
-    "node_modules/fsevents": {
-      "version": "2.3.2",
-      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
-      "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
-      "hasInstallScript": true,
-      "optional": true,
-      "os": [
-        "darwin"
-      ],
-      "peer": true,
-      "engines": {
-        "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
-      }
-    },
     "node_modules/get-caller-file": {
       "version": "2.0.5",
       "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-2.0.5.tgz",
@@ -1500,6 +1487,12 @@
         }
       }
     },
+    "node_modules/node-which": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/node-which/-/node-which-1.0.0.tgz",
+      "integrity": "sha512-PVVbv6DyDc3VkTizcd/7Xchn3NDh+OUnQkrHxgumQ+2lwoWE36KuQClfAVjTwEh3T0jzb1WHrbgCol5HbBZqdQ==",
+      "deprecated": "please use 'which'"
+    },
     "node_modules/normalize-path": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-3.0.0.tgz",
@@ -2311,9 +2304,9 @@
       }
     },
     "node_modules/webdriver-installer": {
-      "version": "1.1.8",
-      "resolved": "https://registry.npmjs.org/webdriver-installer/-/webdriver-installer-1.1.8.tgz",
-      "integrity": "sha512-Ptgz8VdhdzMPNDqVl7Z24n7vMIC+4wPM7C3HgU2Ikc70IXKqIUx6z+kooVs+ZKaUUvEhAhtxbs0kwqR5IERPvA==",
+      "version": "1.1.9",
+      "resolved": "https://registry.npmjs.org/webdriver-installer/-/webdriver-installer-1.1.9.tgz",
+      "integrity": "sha512-lWoCiOC9LvmGOgsTGCvu4opZxPBA76cPPbp93peSrO3djSLg5C6yDiyeWy+jN4uj3LHISZ5GTfjVOJmCE04OUQ==",
       "dependencies": {
         "node-fetch": "^2.6.7",
         "regedit": "^5.0.0",
@@ -3180,13 +3173,6 @@
       "resolved": "https://registry.npmjs.org/fs.realpath/-/fs.realpath-1.0.0.tgz",
       "integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8="
     },
-    "fsevents": {
-      "version": "2.3.2",
-      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
-      "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
-      "optional": true,
-      "peer": true
-    },
     "get-caller-file": {
       "version": "2.0.5",
       "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-2.0.5.tgz",
@@ -3621,6 +3607,11 @@
         "whatwg-url": "^5.0.0"
       }
     },
+    "node-which": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/node-which/-/node-which-1.0.0.tgz",
+      "integrity": "sha512-PVVbv6DyDc3VkTizcd/7Xchn3NDh+OUnQkrHxgumQ+2lwoWE36KuQClfAVjTwEh3T0jzb1WHrbgCol5HbBZqdQ=="
+    },
     "normalize-path": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-3.0.0.tgz",
@@ -4232,9 +4223,9 @@
       }
     },
     "webdriver-installer": {
-      "version": "1.1.8",
-      "resolved": "https://registry.npmjs.org/webdriver-installer/-/webdriver-installer-1.1.8.tgz",
-      "integrity": "sha512-Ptgz8VdhdzMPNDqVl7Z24n7vMIC+4wPM7C3HgU2Ikc70IXKqIUx6z+kooVs+ZKaUUvEhAhtxbs0kwqR5IERPvA==",
+      "version": "1.1.9",
+      "resolved": "https://registry.npmjs.org/webdriver-installer/-/webdriver-installer-1.1.9.tgz",
+      "integrity": "sha512-lWoCiOC9LvmGOgsTGCvu4opZxPBA76cPPbp93peSrO3djSLg5C6yDiyeWy+jN4uj3LHISZ5GTfjVOJmCE04OUQ==",
       "requires": {
         "node-fetch": "^2.6.7",
         "regedit": "^5.0.0",
diff --git a/package.json b/package.json
index e03e756..62e5771 100644
--- a/package.json
+++ b/package.json
@@ -18,8 +18,9 @@
   "author": "Joey Parrish <joeyparrish@google.com>",
   "dependencies": {
     "lodash": "^4.17.21",
+    "node-which": "^1.0.0",
     "wd": "^1.14.0",
-    "webdriver-installer": "^1.1.8"
+    "webdriver-installer": "^1.1.9"
   },
   "peerDependencies": {
     "karma": "^6.2.0"