diff --git a/scripts/symbols/import_project_symbols.php b/scripts/symbols/import_project_symbols.php
index 84e5cea608..8aef684a40 100755
--- a/scripts/symbols/import_project_symbols.php
+++ b/scripts/symbols/import_project_symbols.php
@@ -1,155 +1,180 @@
 #!/usr/bin/env php
 <?php
 
 /*
- * Copyright 2011 Facebook, Inc.
+ * Copyright 2012 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
 $root = dirname(dirname(dirname(__FILE__)));
 require_once $root.'/scripts/__init_script__.php';
 
-phutil_require_module('phutil', 'console');
+$args = new PhutilArgumentParser($argv);
+$args->setSynopsis(<<<EOSYNOPSIS
+**import_project_symbols.php** [__options__] __project_name__ < symbols
 
-if ($argc !== 2) {
-  echo phutil_console_format(
-    "usage: import_project_symbols.php __project_name__ < __symbol_file__\n");
-  exit(1);
+  Import project symbols (symbols are read from stdin).
+EOSYNOPSIS
+  );
+$args->parseStandardArguments();
+$args->parse(
+  array(
+    array(
+      'name'      => 'ignore-duplicates',
+      'help'      => 'Ignore duplicate symbols, choosing one at random. By '.
+                     'default, this script throws if given duplicate '.
+                     'symbols.',
+    ),
+    array(
+      'name'      => 'more',
+      'wildcard'  => true,
+    ),
+  ));
+
+$ignore_duplicates = $args->getArg('ignore-duplicates');
+$more = $args->getArg('more');
+if (count($more) !== 1) {
+  $args->printHelpAndExit();
 }
 
-$project_name = $argv[1];
+$project_name = head($more);
 $project = id(new PhabricatorRepositoryArcanistProject())->loadOneWhere(
   'name = %s',
   $project_name);
 
 if (!$project) {
   // TODO: Provide a less silly way to do this explicitly, or just do it right
   // here.
   echo "Project '{$project_name}' is unknown. Upload a diff to implicitly ".
        "create it.\n";
   exit(1);
 }
 
 echo "Parsing input from stdin...\n";
 $input = file_get_contents('php://stdin');
 $input = trim($input);
 $input = explode("\n", $input);
 
 $map = array();
 $symbols = array();
 foreach ($input as $key => $line) {
   $line_no = $key + 1;
   $matches = null;
   $ok = preg_match('/^([^ ]+) ([^ ]+) ([^ ]+) (\d+) (.*)$/', $line, $matches);
   if (!$ok) {
     throw new Exception(
       "Line #{$line_no} of input is invalid. Expected five space-delimited ".
       "fields: symbol name, symbol type, symbol language, line number, path. ".
       "For example:\n\n".
       "idx function php 13 /path/to/some/file.php\n\n".
       "Actual line was:\n\n".
       "{$line}");
   }
   list($all, $name, $type, $lang, $line_number, $path) = $matches;
 
   if (isset($map[$name][$type][$lang])) {
-    $previous = $map[$name][$type][$lang] + 1;
-    throw new Exception(
-      "Line #{$line_no} of input is invalid. It specifies a duplicate symbol ".
-      "(same name, language, and type) which has already been defined ".
-      "elsewhere. You must preprocess the symbol list to remove duplicates ".
-      "and choose exactly one master definition for each symbol. This symbol ".
-      "was previously defined on line #{$previous}.\n\n".
-      "Line #{$line_no}:\n".
-      $line."\n\n".
-      "Line #{$previous}:\n".
-      $input[$previous - 1]);
+    if ($ignore_duplicates) {
+      echo "Ignoring duplicate definition of '{$name}' on line {$line_no}.\n";
+    } else {
+      $previous = $map[$name][$type][$lang] + 1;
+      throw new Exception(
+        "Line #{$line_no} of input is invalid. It specifies a duplicate ".
+        "symbol (same name, language, and type) which has already been ".
+        "defined elsewhere. You must preprocess the symbol list to remove ".
+        "duplicates and choose exactly one master definition for each ".
+        "symbol, or specify --ignore-duplicates. This symbol was previously ".
+        "defined on line #{$previous}.\n\n".
+        "Line #{$line_no}:\n".
+        $line."\n\n".
+        "Line #{$previous}:\n".
+        $input[$previous - 1]);
+    }
   } else {
     $map[$name][$type][$lang] = $key;
   }
 
   if (strlen($name) > 128) {
     throw new Exception(
       "Symbol name '{$name}' defined on line #{$line_no} is too long, maximum ".
       "symbol name length is 128 characters.");
   }
 
   if (strlen($type) > 12) {
     throw new Exception(
       "Symbol type '{$type}' defined on line #{$line_no} is too long, maximum ".
       "symbol type length is 12 characters.");
   }
 
   if (strlen($lang) > 32) {
     throw new Exception(
       "Symbol language '{$lang}' defined on line #{$line_no} is too long, ".
       "maximum symbol language length is 32 characters.");
   }
 
   if (!strlen($path) || $path[0] != 0) {
     throw new Exception(
       "Path '{$path}' defined on line #{$line_no} is invalid. Paths should be ".
       "begin with '/' and specify a path from the root of the project, like ".
       "'/src/utils/utils.php'.");
   }
 
   $symbols[] = array(
     'name' => $name,
     'type' => $type,
     'lang' => $lang,
     'line' => $line_number,
     'path' => $path,
   );
 }
 
 echo "Looking up path IDs...\n";
 $path_map = PhabricatorRepositoryCommitChangeParserWorker::lookupOrCreatePaths(
   ipull($symbols, 'path'));
 
 $symbol = new PhabricatorRepositorySymbol();
 $conn_w = $symbol->establishConnection('w');
 
 echo "Preparing queries...\n";
 $sql = array();
 foreach ($symbols as $dict) {
   $sql[] = qsprintf(
     $conn_w,
     '(%d, %s, %s, %s, %d, %d)',
     $project->getID(),
     $dict['name'],
     $dict['type'],
     $dict['lang'],
     $dict['line'],
     $path_map[$dict['path']]);
 }
 
 echo "Purging old symbols...\n";
 queryfx(
   $conn_w,
   'DELETE FROM %T WHERE arcanistProjectID = %d',
   $symbol->getTableName(),
   $project->getID());
 
 echo "Loading ".number_format(count($sql))." symbols...\n";
 foreach (array_chunk($sql, 128) as $chunk) {
   queryfx(
     $conn_w,
     'INSERT INTO %T
       (arcanistProjectID, symbolName, symbolType, symbolLanguage, lineNumber,
         pathID) VALUES %Q',
     $symbol->getTableName(),
     implode(', ', $chunk));
 }
 
 echo "Done.\n";