diff --git a/src/helpers/injectRefreshEntry.js b/src/helpers/injectRefreshEntry.js
index 636a4792..c0444097 100644
--- a/src/helpers/injectRefreshEntry.js
+++ b/src/helpers/injectRefreshEntry.js
@@ -1,3 +1,5 @@
+const querystring = require('querystring');
+
 /** @typedef {string | string[] | import('webpack').Entry} StaticEntry */
 /** @typedef {StaticEntry | import('webpack').EntryFunc} WebpackEntry */
 
@@ -7,27 +9,38 @@
  * @param {import('../types').ReactRefreshPluginOptions} [options] Configuration options for this plugin.
  * @returns {WebpackEntry} An injected entry object.
  */
-const injectRefreshEntry = (originalEntry, options) => {
-  const sockHost = options.sockHost ? `&sockHost=${options.sockHost}` : '';
-  const sockPort = options.sockPort ? `&sockPort=${options.sockPort}` : '';
-  const sockPath = options.sockPath ? `&sockPath=${options.sockPath}` : '';
-  const queryParams = `?options${sockHost}${sockPort}${sockPath}`;
-  const entryInjects = [
-    // Legacy WDS SockJS integration
-    options.useLegacyWDSSockets && require.resolve('../runtime/LegacyWebpackDevServerSocket'),
+function injectRefreshEntry(originalEntry, options) {
+  let resourceQuery = {};
+  if (options.overlay) {
+    options.overlay.sockHost && (resourceQuery.sockHost = options.overlay.sockHost);
+    options.overlay.sockPath && (resourceQuery.sockPath = options.overlay.sockPath);
+    options.overlay.sockPort && (resourceQuery.sockPort = options.overlay.sockPort);
+  }
+
+  // We don't need to URI encode the resourceQuery as it will be parsed by Webpack
+  const queryString = querystring.stringify(resourceQuery, null, null, {
+    encodeURIComponent: (string) => string,
+  });
+
+  const prependEntries = [
     // React-refresh runtime
     require.resolve('../runtime/ReactRefreshEntry'),
+  ];
+
+  const appendEntries = [
+    // Legacy WDS SockJS integration
+    options.useLegacyWDSSockets && require.resolve('../runtime/LegacyWDSSocketEntry'),
     // Error overlay runtime
-    options.overlay && options.overlay.entry + queryParams,
+    options.overlay && options.overlay.entry + (queryString && `?${queryString}`),
   ].filter(Boolean);
 
   // Single string entry point
   if (typeof originalEntry === 'string') {
-    return [...entryInjects, originalEntry];
+    return [...prependEntries, originalEntry, ...appendEntries];
   }
   // Single array entry point
   if (Array.isArray(originalEntry)) {
-    return [...entryInjects, ...originalEntry];
+    return [...prependEntries, ...originalEntry, ...appendEntries];
   }
   // Multiple entry points
   if (typeof originalEntry === 'object') {
@@ -48,6 +61,6 @@ const injectRefreshEntry = (originalEntry, options) => {
   }
 
   throw new Error('Failed to parse the Webpack `entry` object!');
-};
+}
 
 module.exports = injectRefreshEntry;
diff --git a/src/helpers/validateOptions.js b/src/helpers/validateOptions.js
index 8ec6b6df..1b219270 100644
--- a/src/helpers/validateOptions.js
+++ b/src/helpers/validateOptions.js
@@ -12,6 +12,18 @@ function isBooleanOrUndefined(name, value) {
   }
 }
 
+function isNumberOrUndefined(name, value) {
+  const valueType = typeof value;
+  if (valueType !== 'undefined' && valueType !== 'number') {
+    throw new Error(
+      [
+        `The "${name}" option, if defined, must be a number.`,
+        `Instead received: "${valueType}".`,
+      ].join('\n')
+    );
+  }
+}
+
 function isStringOrUndefined(name, value) {
   const valueType = typeof value;
   if (valueType !== 'undefined' && valueType !== 'string') {
@@ -69,9 +81,12 @@ function validateOptions(options) {
     typeof defaultedOptions.overlay !== 'undefined' &&
     typeof defaultedOptions.overlay !== 'boolean'
   ) {
-    const { entry, module: overlayModule } = defaultedOptions.overlay;
+    const { entry, module: overlayModule, sockHost, sockPath, sockPort } = defaultedOptions.overlay;
     isStringOrUndefined('overlay.entry', entry);
     isStringOrUndefined('overlay.module', overlayModule);
+    isStringOrUndefined('overlay.sockHost', sockHost);
+    isStringOrUndefined('overlay.sockPath', sockPath);
+    isNumberOrUndefined('overlay.sockPort', sockPort);
 
     defaultedOptions.overlay = {
       ...defaultedOptions.overlay,
diff --git a/src/runtime/ErrorOverlayEntry.js b/src/runtime/ErrorOverlayEntry.js
index 5f516ad6..72330286 100644
--- a/src/runtime/ErrorOverlayEntry.js
+++ b/src/runtime/ErrorOverlayEntry.js
@@ -73,7 +73,10 @@ function compileMessageHandler(message) {
 
 let overrides = {};
 if (__resourceQuery) {
-  overrides = require('querystring').parse(__resourceQuery.slice(1));
+  const searchParams = new URLSearchParams(__resourceQuery.slice(1));
+  searchParams.forEach(function (value, key) {
+    overrides[key] = value;
+  });
 }
 
 // Registers handlers for compile errors
diff --git a/src/types.js b/src/types.js
index 2a719f51..809f343d 100644
--- a/src/types.js
+++ b/src/types.js
@@ -1,7 +1,10 @@
 /**
  * @typedef {Object} ErrorOverlayOptions
  * @property {string} [entry] Path to a JS file that sets up the error overlay integration.
- * @property {string} module The error overlay module to use.
+ * @property {string} [module] The error overlay module to use.
+ * @property {string} [sockHost] The socket host to use.
+ * @property {string} [sockPath] The socket path to use.
+ * @property {number} [sockPort] The socket port to use.
  */
 
 /**
@@ -9,9 +12,6 @@
  * @property {boolean} [disableRefreshCheck] Disables detection of react-refresh's Babel plugin. (Deprecated since v0.3.0)
  * @property {boolean} [forceEnable] Enables the plugin forcefully.
  * @property {boolean | ErrorOverlayOptions} [overlay] Modifies how the error overlay integration works in the plugin.
- * @property {string} [sockHost] The socket host to use for the error overlay integration.
- * @property {string} [sockPath] The socket path to use for the error overlay integration.
- * @property {number} [sockPort] The socket port to use for the error overlay integration.
  * @property {boolean} [useLegacyWDSSockets] Uses a custom SocketJS implementation for older versions of webpack-dev-server.
  */