diff --git a/src/toolset/ArcanistPrompt.php b/src/toolset/ArcanistPrompt.php
index 24523596..caff32c6 100644
--- a/src/toolset/ArcanistPrompt.php
+++ b/src/toolset/ArcanistPrompt.php
@@ -1,312 +1,320 @@
 <?php
 
 final class ArcanistPrompt
   extends Phobject {
 
   private $key;
   private $workflow;
   private $description;
   private $query;
 
   public function setKey($key) {
     $this->key = $key;
     return $this;
   }
 
   public function getKey() {
     return $this->key;
   }
 
   public function setWorkflow(ArcanistWorkflow $workflow) {
     $this->workflow = $workflow;
     return $this;
   }
 
   public function getWorkflow() {
     return $this->workflow;
   }
 
   public function setDescription($description) {
     $this->description = $description;
     return $this;
   }
 
   public function getDescription() {
     return $this->description;
   }
 
   public function setQuery($query) {
     $this->query = $query;
     return $this;
   }
 
   public function getQuery() {
     return $this->query;
   }
 
   public function execute() {
     $workflow = $this->getWorkflow();
     if ($workflow) {
       $workflow_ok = $workflow->hasPrompt($this->getKey());
     } else {
       $workflow_ok = false;
     }
 
     if (!$workflow_ok) {
       throw new Exception(
         pht(
           'Prompt ("%s") is executing, but it is not properly bound to the '.
           'invoking workflow. You may have called "newPrompt()" to execute a '.
           'prompt instead of "getPrompt()". Use "newPrompt()" when defining '.
           'prompts and "getPrompt()" when executing them.',
           $this->getKey()));
     }
 
     $query = $this->getQuery();
     if (!strlen($query)) {
       throw new Exception(
         pht(
           'Prompt ("%s") has no query text!',
           $this->getKey()));
     }
 
     $options = '[y/N/?]';
     $default = 'n';
 
     $saved_response = $this->getSavedResponse();
 
     try {
       phutil_console_require_tty();
     } catch (PhutilConsoleStdinNotInteractiveException $ex) {
       // TOOLSETS: Clean this up to provide more details to the user about how
       // they can configure prompts to be answered.
 
       // Throw after echoing the prompt so the user has some idea what happened.
       echo $query."\n";
       throw $ex;
     }
 
-    // NOTE: We're making stdin nonblocking so that we can respond to signals
-    // immediately. If we don't, and you ^C during a prompt, the program does
-    // not handle the signal until fgets() returns.
-
     $stdin = fopen('php://stdin', 'r');
     if (!$stdin) {
       throw new Exception(pht('Failed to open stdin for reading.'));
     }
 
-    $ok = stream_set_blocking($stdin, false);
-    if (!$ok) {
-      throw new Exception(pht('Unable to set stdin nonblocking.'));
+    // NOTE: We're making stdin nonblocking so that we can respond to signals
+    // immediately. If we don't, and you ^C during a prompt, the program does
+    // not handle the signal until fgets() returns.
+
+    // On Windows, we skip this because stdin can not be made nonblocking.
+
+    if (!phutil_is_windows()) {
+      $ok = stream_set_blocking($stdin, false);
+      if (!$ok) {
+        throw new Exception(pht('Unable to set stdin nonblocking.'));
+      }
     }
 
     echo "\n";
 
     $result = null;
     $is_saved = false;
     while (true) {
       if ($saved_response !== null) {
         $is_saved = true;
 
         $response = $saved_response;
         $saved_response = null;
       } else {
         echo tsprintf(
           '**<bg:cyan> %s </bg>** %s %s ',
           '>>>',
           $query,
           $options);
 
-        while (true) {
-          $is_saved = false;
+        $is_saved = false;
 
-          $read = array($stdin);
-          $write = array();
-          $except = array();
+        if (phutil_is_windows()) {
+          $response = fgets($stdin);
+        } else {
+          while (true) {
+            $read = array($stdin);
+            $write = array();
+            $except = array();
+
+            $ok = @stream_select($read, $write, $except, 1);
+            if ($ok === false) {
+              // NOTE: We may be interrupted by a system call, particularly if
+              // the window is resized while a prompt is shown and the terminal
+              // sends SIGWINCH.
+
+              // If we are, just continue below and try to read from stdin. If
+              // we were interrupted, we should read nothing and continue
+              // normally. If the pipe is broken, the read should fail.
+            }
 
-          $ok = @stream_select($read, $write, $except, 1);
-          if ($ok === false) {
-            // NOTE: We may be interrupted by a system call, particularly if
-            // the window is resized while a prompt is shown and the terminal
-            // sends SIGWINCH.
+            $response = '';
+            while (true) {
+              $bytes = fread($stdin, 8192);
+              if ($bytes === false) {
+                throw new Exception(
+                  pht('fread() from stdin failed with an error.'));
+              }
 
-            // If we are, just continue below and try to read from stdin. If
-            // we were interrupted, we should read nothing and continue
-            // normally. If the pipe is broken, the read should fail.
-          }
+              if (!strlen($bytes)) {
+                break;
+              }
 
-          $response = '';
-          while (true) {
-            $bytes = fread($stdin, 8192);
-            if ($bytes === false) {
-              throw new Exception(
-                pht('fread() from stdin failed with an error.'));
+              $response .= $bytes;
             }
 
-            if (!strlen($bytes)) {
-              break;
+            if (!strlen($response)) {
+              continue;
             }
 
-            $response .= $bytes;
-          }
-
-          if (!strlen($response)) {
-            continue;
+            break;
           }
-
-          break;
         }
 
         $response = trim($response);
         if (!strlen($response)) {
           $response = $default;
         }
       }
 
       $save_scope = null;
       if (!$is_saved) {
         $matches = null;
         if (preg_match('(^(.*)([!*])\z)', $response, $matches)) {
           $response = $matches[1];
 
           if ($matches[2] === '*') {
             $save_scope = ArcanistConfigurationSource::SCOPE_USER;
           } else {
             $save_scope = ArcanistConfigurationSource::SCOPE_WORKING_COPY;
           }
         }
       }
 
       if (phutil_utf8_strtolower($response) == 'y') {
         $result = true;
         break;
       }
 
       if (phutil_utf8_strtolower($response) == 'n') {
         $result = false;
         break;
       }
 
       if (phutil_utf8_strtolower($response) == '?') {
         echo tsprintf(
           "\n<bg:green>** %s **</bg> **%s**\n\n",
           pht('PROMPT'),
           $this->getKey());
 
         echo tsprintf(
           "%s\n",
           $this->getDescription());
 
         echo tsprintf("\n");
 
         echo tsprintf(
           "%s\n",
           pht(
             'The default response to this prompt is "%s".',
             $default));
 
         echo tsprintf("\n");
 
         echo tsprintf(
           "%?\n",
           pht(
             'Use "*" after a response to save it in user configuration.'));
 
         echo tsprintf(
           "%?\n",
           pht(
             'Use "!" after a response to save it in working copy '.
             'configuration.'));
 
         echo tsprintf(
           "%?\n",
           pht(
             'Run "arc help prompts" for detailed help on configuring '.
             'responses.'));
 
         echo tsprintf("\n");
 
         continue;
       }
     }
 
     if ($save_scope !== null) {
       $this->saveResponse($save_scope, $response);
     }
 
     if ($is_saved) {
       echo tsprintf(
         "<bg:cyan>** %s **</bg> %s **<%s>**\n".
         "<bg:cyan>** %s **</bg> (%s)\n\n",
         '>>>',
         $query,
         $response,
         '>>>',
         pht(
           'Using saved response to prompt "%s".',
           $this->getKey()));
     }
 
     if (!$result) {
       throw new ArcanistUserAbortException();
     }
   }
 
   private function getSavedResponse() {
     $config_key = ArcanistArcConfigurationEngineExtension::KEY_PROMPTS;
     $workflow = $this->getWorkflow();
 
     $config = $workflow->getConfig($config_key);
 
     $prompt_key = $this->getKey();
 
     $prompt_response = null;
     foreach ($config as $response) {
       if ($response->getPrompt() === $prompt_key) {
         $prompt_response = $response;
       }
     }
 
     if ($prompt_response === null) {
       return null;
     }
 
     return $prompt_response->getResponse();
   }
 
   private function saveResponse($scope, $response_value) {
     $config_key = ArcanistArcConfigurationEngineExtension::KEY_PROMPTS;
     $workflow = $this->getWorkflow();
 
     echo tsprintf(
       "<bg:green>** %s **</bg> %s\n",
       pht('SAVE PROMPT'),
       pht(
         'Saving response "%s" to prompt "%s".',
         $response_value,
         $this->getKey()));
 
     $source_list = $workflow->getConfigurationSourceList();
     $source = $source_list->getWritableSourceFromScope($scope);
 
     $response_list = $source_list->getConfigFromScopes(
       $config_key,
       array($scope));
 
     foreach ($response_list as $key => $response) {
       if ($response->getPrompt() === $this->getKey()) {
         unset($response_list[$key]);
       }
     }
 
     if ($response_value !== null) {
       $response_list[] = id(new ArcanistPromptResponse())
         ->setPrompt($this->getKey())
         ->setResponse($response_value);
     }
 
     $option = $source_list->getConfigOption($config_key);
     $option->writeValue($source, $response_list);
   }
 
 }