diff --git a/src/xsprintf/PhutilTerminalString.php b/src/xsprintf/PhutilTerminalString.php
index 8d99b093..1d42f288 100644
--- a/src/xsprintf/PhutilTerminalString.php
+++ b/src/xsprintf/PhutilTerminalString.php
@@ -1,75 +1,82 @@
 <?php
 
 /**
  * String escaped for terminal output. See @{function:tsprintf}.
  */
 final class PhutilTerminalString extends Phobject {
 
   private $string;
 
   public function __construct($string) {
     $this->string = $string;
   }
 
   public function __toString() {
     return $this->string;
   }
 
   public function applyWrap() {
     $string = (string)$this;
     $string = phutil_console_wrap($string);
     return new self($string);
   }
 
   public function applyIndent($depth, $with_prefix = true) {
     $string = (string)$this;
     $string = phutil_console_wrap($string, $depth, $with_prefix);
     return new self($string);
   }
 
   public static function escapeStringValue($value, $allow_whitespace) {
     if ($value instanceof PhutilTerminalString) {
       return (string)$value;
     }
 
     $value = (string)$value;
 
     static $escape_map;
     if ($escape_map === null) {
       $escape_map = array(
         chr(0x00) => '<NUL>',
         chr(0x07) => '<BEL>',
         chr(0x08) => '<BS>',
         chr(0x09) => '<TAB>',
         chr(0x0A) => '<LF>',
         chr(0x0D) => '<CR>',
         chr(0x1B) => '<ESC>',
         chr(0x7F) => '<DEL>',
       );
 
       for ($ii = 0; $ii < 32; $ii++) {
         $c = chr($ii);
         if (empty($escape_map[$c])) {
           $escape_map[$c] = sprintf('<0x%02X>', $ii);
         }
       }
     }
 
     $map = $escape_map;
     if ($allow_whitespace) {
       unset($map["\r"]);
       unset($map["\n"]);
       unset($map["\t"]);
     }
 
     $value = str_replace(array_keys($map), array_values($map), $value);
 
     // In this mode, we additionally escape any <CR> which is not immediately
     // followed by <LF>.
     if ($allow_whitespace) {
       $value = preg_replace('/\r(?!\n)/', '<CR>', $value);
     }
 
+    // See T13209. If we print certain invalid unicode byte sequences to the
+    // terminal under "cmd.exe", the entire string is silently dropped. Avoid
+    // printing invalid sequences.
+    if (phutil_is_windows()) {
+      $value = phutil_utf8ize($value);
+    }
+
     return $value;
   }
 }