diff --git a/src/search/PhutilSearchStemmer.php b/src/search/PhutilSearchStemmer.php
index c5998ca..c4a8604 100644
--- a/src/search/PhutilSearchStemmer.php
+++ b/src/search/PhutilSearchStemmer.php
@@ -1,70 +1,74 @@
 <?php
 
 final class PhutilSearchStemmer
   extends Phobject {
 
   public function stemToken($token) {
     $token = $this->normalizeToken($token);
     return $this->applyStemmer($token);
   }
 
   public function stemCorpus($corpus) {
+    $corpus = $this->normalizeCorpus($corpus);
     $tokens = preg_split('/[^a-zA-Z0-9\x7F-\xFF._]+/', $corpus);
 
     $words = array();
     foreach ($tokens as $key => $token) {
       $token = trim($token, '._');
 
       if (strlen($token) < 3) {
         continue;
       }
 
-      $normal_word = $this->normalizeToken($token);
-      $words[$normal_word] = $normal_word;
+      $words[$token] = $token;
     }
 
     $stems = array();
-    foreach ($words as $normal_word) {
-      $stems[] = $this->applyStemmer($normal_word);
+    foreach ($words as $word) {
+      $stems[] = $this->applyStemmer($word);
     }
 
     return implode(' ', $stems);
   }
 
   private function normalizeToken($token) {
     return phutil_utf8_strtolower($token);
   }
 
+  private function normalizeCorpus($corpus) {
+    return phutil_utf8_strtolower($corpus);
+  }
+
   /**
    * @phutil-external-symbol class Porter
    */
   private function applyStemmer($normalized_token) {
     // If the token has internal punctuation, handle it literally. This
     // deals with things like domain names, Conduit API methods, and other
     // sorts of informal tokens.
     if (preg_match('/[._]/', $normalized_token)) {
       return $normalized_token;
     }
 
     static $loaded;
 
     if ($loaded === null) {
       $root = dirname(phutil_get_library_root('phutil'));
       require_once $root.'/externals/porter-stemmer/src/Porter.php';
       $loaded = true;
     }
 
 
     $stem = Porter::stem($normalized_token);
 
     // If the stem is too short, it won't be a candidate for indexing. These
     // tokens are also likely to be acronyms (like "DNS") rather than real
     // English words.
     if (strlen($stem) < 3) {
       return $normalized_token;
     }
 
     return $stem;
   }
 
 }