diff --git a/src/Context/ProcessContext.php b/src/Context/ProcessContext.php
index 2b62ac8..64fca30 100644
--- a/src/Context/ProcessContext.php
+++ b/src/Context/ProcessContext.php
@@ -29,10 +29,10 @@ final class ProcessContext extends AbstractContext
     ];
 
     private const XDEBUG_OPTIONS = [
-        "xdebug.mode" => "debug",
-        "xdebug.start_with_request" => "default",
-        "xdebug.client_port" => "9003",
-        "xdebug.client_host" => "localhost",
+        "xdebug.mode",
+        "xdebug.start_with_request",
+        "xdebug.client_port",
+        "xdebug.client_host",
     ];
 
     /** @var non-empty-string|null External version of SCRIPT_PATH if inside a PHAR. */
@@ -222,10 +222,12 @@ private static function buildOptions(): array
 
         // This copies any ini values set via the command line (e.g., a debug run in PhpStorm)
         // to the child process, instead of relying only on those set in an ini file.
-        if (\ini_get("xdebug.mode") !== false) {
-            foreach (self::XDEBUG_OPTIONS as $option => $defaultValue) {
+        if (\extension_loaded('xdebug') && \ini_get("xdebug.mode") !== false) {
+            foreach (self::XDEBUG_OPTIONS as $option) {
                 $iniValue = \ini_get($option);
-                $options[$option] = $iniValue === false ? $defaultValue : $iniValue;
+                if ($iniValue !== false) {
+                    $options[$option] = $iniValue;
+                }
             }
         }