diff --git a/src/lint/linter/ArcanistPEP8Linter.php b/src/lint/linter/ArcanistPEP8Linter.php
index 82ab607f..03811358 100644
--- a/src/lint/linter/ArcanistPEP8Linter.php
+++ b/src/lint/linter/ArcanistPEP8Linter.php
@@ -1,126 +1,126 @@
 <?php
 
 /**
  * Uses "pep8.py" to enforce PEP8 rules for Python.
  */
 final class ArcanistPEP8Linter extends ArcanistExternalLinter {
 
   public function getInfoName() {
     return 'pep8';
   }
 
   public function getInfoURI() {
     return 'https://pypi.python.org/pypi/pep8';
   }
 
   public function getInfoDescription() {
     return pht(
       'pep8 is a tool to check your Python code against some of the '.
       'style conventions in PEP 8.');
   }
 
   public function getLinterName() {
     return 'PEP8';
   }
 
   public function getLinterConfigurationName() {
     return 'pep8';
   }
 
   protected function getDefaultFlags() {
     return $this->getDeprecatedConfiguration('lint.pep8.options', array());
   }
 
   public function shouldUseInterpreter() {
     return ($this->getDefaultBinary() !== 'pep8');
   }
 
   public function getDefaultInterpreter() {
     return 'python2.6';
   }
 
   public function getDefaultBinary() {
     if (Filesystem::binaryExists('pep8')) {
       return 'pep8';
     }
 
     $old_prefix = $this->getDeprecatedConfiguration('lint.pep8.prefix');
     $old_bin = $this->getDeprecatedConfiguration('lint.pep8.bin');
     if ($old_prefix || $old_bin) {
       $old_bin = nonempty($old_bin, 'pep8');
       return $old_prefix.'/'.$old_bin;
     }
 
     $arc_root = dirname(phutil_get_library_root('arcanist'));
     return $arc_root.'/externals/pep8/pep8.py';
   }
 
   public function getVersion() {
     list($stdout) = execx('%C --version', $this->getExecutableCommand());
 
     $matches = array();
-    if (preg_match('/^(?P<version>\d+\.\d+\.\d+)$/', $stdout, $matches)) {
+    if (preg_match('/^(?P<version>\d+\.\d+(?:\.\d+)?)\b/', $stdout, $matches)) {
       return $matches['version'];
     } else {
       return false;
     }
   }
 
   public function getInstallInstructions() {
     return pht('Install PEP8 using `easy_install pep8`.');
   }
 
   protected function parseLinterOutput($path, $err, $stdout, $stderr) {
     $lines = phutil_split_lines($stdout, false);
 
     $messages = array();
     foreach ($lines as $line) {
       $matches = null;
       if (!preg_match('/^(.*?):(\d+):(\d+): (\S+) (.*)$/', $line, $matches)) {
         continue;
       }
       foreach ($matches as $key => $match) {
         $matches[$key] = trim($match);
       }
       $message = new ArcanistLintMessage();
       $message->setPath($path);
       $message->setLine($matches[2]);
       $message->setChar($matches[3]);
       $message->setCode($matches[4]);
       $message->setName('PEP8 '.$matches[4]);
       $message->setDescription($matches[5]);
       $message->setSeverity($this->getLintMessageSeverity($matches[4]));
 
       $messages[] = $message;
     }
 
     if ($err && !$messages) {
       return false;
     }
 
     return $messages;
   }
 
   protected function getDefaultMessageSeverity($code) {
     if (preg_match('/^W/', $code)) {
       return ArcanistLintSeverity::SEVERITY_WARNING;
     } else {
       return ArcanistLintSeverity::SEVERITY_ERROR;
     }
   }
 
   protected function getLintCodeFromLinterConfigurationKey($code) {
     if (!preg_match('/^(E|W)\d+$/', $code)) {
       throw new Exception(
         pht(
           'Unrecognized lint message code "%s". Expected a valid PEP8 '.
           'lint code like "%s" or "%s".',
           $code,
           'E101',
           'W291'));
     }
 
     return $code;
   }
 
 }