diff --git a/src/applications/diviner/atomizer/DivinerPHPAtomizer.php b/src/applications/diviner/atomizer/DivinerPHPAtomizer.php
index 36616897f2..201055a15c 100644
--- a/src/applications/diviner/atomizer/DivinerPHPAtomizer.php
+++ b/src/applications/diviner/atomizer/DivinerPHPAtomizer.php
@@ -1,329 +1,338 @@
 <?php
 
 final class DivinerPHPAtomizer extends DivinerAtomizer {
 
   protected function newAtom($type) {
     return parent::newAtom($type)->setLanguage('php');
   }
 
   protected function executeAtomize($file_name, $file_data) {
     $future = PhutilXHPASTBinary::getParserFuture($file_data);
     $tree = XHPASTTree::newFromDataAndResolvedExecFuture(
       $file_data,
       $future->resolve());
 
     $atoms = array();
     $root = $tree->getRootNode();
 
     $func_decl = $root->selectDescendantsOfType('n_FUNCTION_DECLARATION');
     foreach ($func_decl as $func) {
       $name = $func->getChildByIndex(2);
 
       // Don't atomize closures
       if ($name->getTypeName() === 'n_EMPTY') {
         continue;
       }
 
       $atom = $this->newAtom(DivinerAtom::TYPE_FUNCTION)
         ->setName($name->getConcreteString())
         ->setLine($func->getLineNumber())
         ->setFile($file_name);
 
       $this->findAtomDocblock($atom, $func);
       $this->parseParams($atom, $func);
       $this->parseReturnType($atom, $func);
 
       $atoms[] = $atom;
     }
 
     $class_types = array(
       DivinerAtom::TYPE_CLASS => 'n_CLASS_DECLARATION',
       DivinerAtom::TYPE_INTERFACE => 'n_INTERFACE_DECLARATION',
     );
     foreach ($class_types as $atom_type => $node_type) {
       $class_decls = $root->selectDescendantsOfType($node_type);
 
       foreach ($class_decls as $class) {
         $name = $class->getChildByIndex(1, 'n_CLASS_NAME');
 
         $atom = $this->newAtom($atom_type)
           ->setName($name->getConcreteString())
           ->setFile($file_name)
           ->setLine($class->getLineNumber());
 
         // This parses `final` and `abstract`.
         $attributes = $class->getChildByIndex(0, 'n_CLASS_ATTRIBUTES');
         foreach ($attributes->selectDescendantsOfType('n_STRING') as $attr) {
           $atom->setProperty($attr->getConcreteString(), true);
         }
 
         // If this exists, it is `n_EXTENDS_LIST`.
         $extends = $class->getChildByIndex(2);
         $extends_class = $extends->selectDescendantsOfType('n_CLASS_NAME');
         foreach ($extends_class as $parent_class) {
           $atom->addExtends(
             $this->newRef(
               DivinerAtom::TYPE_CLASS,
               $parent_class->getConcreteString()));
         }
 
         // If this exists, it is `n_IMPLEMENTS_LIST`.
         $implements = $class->getChildByIndex(3);
         $iface_names = $implements->selectDescendantsOfType('n_CLASS_NAME');
         foreach ($iface_names as $iface_name) {
           $atom->addExtends(
             $this->newRef(
               DivinerAtom::TYPE_INTERFACE,
               $iface_name->getConcreteString()));
         }
 
         $this->findAtomDocblock($atom, $class);
 
         $methods = $class->selectDescendantsOfType('n_METHOD_DECLARATION');
         foreach ($methods as $method) {
           $matom = $this->newAtom(DivinerAtom::TYPE_METHOD);
 
           $this->findAtomDocblock($matom, $method);
 
           $attribute_list = $method->getChildByIndex(0);
           $attributes = $attribute_list->selectDescendantsOfType('n_STRING');
           if ($attributes) {
             foreach ($attributes as $attribute) {
               $attr = strtolower($attribute->getConcreteString());
               switch ($attr) {
                 case 'final':
                 case 'abstract':
                 case 'static':
                   $matom->setProperty($attr, true);
                   break;
                 case 'public':
                 case 'protected':
                 case 'private':
                   $matom->setProperty('access', $attr);
                   break;
               }
             }
           } else {
             $matom->setProperty('access', 'public');
           }
 
           $this->parseParams($matom, $method);
 
           $matom->setName($method->getChildByIndex(2)->getConcreteString());
           $matom->setLine($method->getLineNumber());
           $matom->setFile($file_name);
 
           $this->parseReturnType($matom, $method);
           $atom->addChild($matom);
 
           $atoms[] = $matom;
         }
 
         $atoms[] = $atom;
       }
     }
 
     return $atoms;
   }
 
   private function parseParams(DivinerAtom $atom, AASTNode $func) {
     $params = $func
       ->getChildByIndex(3, 'n_DECLARATAION_PARAMETER_LIST')
       ->selectDescendantsOfType('n_DECLARATION_PARAMETER');
 
     $param_spec = array();
 
     if ($atom->getDocblockRaw()) {
       $metadata = $atom->getDocblockMeta();
     } else {
       $metadata = array();
     }
 
     $docs = idx($metadata, 'param');
     if ($docs) {
-      $docs = explode("\n", $docs);
+      $docs = (array)$docs;
       $docs = array_filter($docs);
     } else {
       $docs = array();
     }
 
     if (count($docs)) {
       if (count($docs) < count($params)) {
         $atom->addWarning(
           pht(
             'This call takes %s parameter(s), but only %s are documented.',
             phutil_count($params),
             phutil_count($docs)));
       }
     }
 
     foreach ($params as $param) {
       $name = $param->getChildByIndex(1)->getConcreteString();
       $dict = array(
         'type'    => $param->getChildByIndex(0)->getConcreteString(),
         'default' => $param->getChildByIndex(2)->getConcreteString(),
       );
 
       if ($docs) {
         $doc = array_shift($docs);
         if ($doc) {
           $dict += $this->parseParamDoc($atom, $doc, $name);
         }
       }
 
       $param_spec[] = array(
         'name' => $name,
       ) + $dict;
     }
 
     if ($docs) {
       foreach ($docs as $doc) {
         if ($doc) {
           $param_spec[] = $this->parseParamDoc($atom, $doc, null);
         }
       }
     }
 
     // TODO: Find `assert_instances_of()` calls in the function body and
     // add their type information here. See T1089.
 
     $atom->setProperty('parameters', $param_spec);
   }
 
   private function findAtomDocblock(DivinerAtom $atom, XHPASTNode $node) {
     $token = $node->getDocblockToken();
     if ($token) {
       $atom->setDocblockRaw($token->getValue());
       return true;
     } else {
       $tokens = $node->getTokens();
       if ($tokens) {
         $prev = head($tokens);
         while ($prev = $prev->getPrevToken()) {
           if ($prev->isAnyWhitespace()) {
             continue;
           }
           break;
         }
 
         if ($prev && $prev->isComment()) {
           $value = $prev->getValue();
           $matches = null;
           if (preg_match('/@(return|param|task|author)/', $value, $matches)) {
             $atom->addWarning(
               pht(
                 'Atom "%s" is preceded by a comment containing `%s`, but '.
                 'the comment is not a documentation comment. Documentation '.
                 'comments must begin with `%s`, followed by a newline. Did '.
                 'you mean to use a documentation comment? (As the comment is '.
                 'not a documentation comment, it will be ignored.)',
                 $atom->getName(),
                 '@'.$matches[1],
                 '/**'));
           }
         }
       }
 
       $atom->setDocblockRaw('');
       return false;
     }
   }
 
   protected function parseParamDoc(DivinerAtom $atom, $doc, $name) {
     $dict = array();
     $split = preg_split('/\s+/', trim($doc), 2);
     if (!empty($split[0])) {
       $dict['doctype'] = $split[0];
     }
 
     if (!empty($split[1])) {
       $docs = $split[1];
 
       // If the parameter is documented like `@param int $num Blah blah ..`,
       // get rid of the `$num` part (which Diviner considers optional). If it
       // is present and different from the declared name, raise a warning.
       $matches = null;
       if (preg_match('/^(\\$\S+)\s+/', $docs, $matches)) {
         if ($name !== null) {
           if ($matches[1] !== $name) {
             $atom->addWarning(
               pht(
                 'Parameter "%s" is named "%s" in the documentation. '.
                 'The documentation may be out of date.',
                 $name,
                 $matches[1]));
           }
         }
         $docs = substr($docs, strlen($matches[0]));
       }
 
       $dict['docs'] = $docs;
     }
 
     return $dict;
   }
 
   private function parseReturnType(DivinerAtom $atom, XHPASTNode $decl) {
     $return_spec = array();
 
     $metadata = $atom->getDocblockMeta();
     $return = idx($metadata, 'return');
 
     $type = null;
     $docs = null;
 
     if (!$return) {
       $return = idx($metadata, 'returns');
       if ($return) {
         $atom->addWarning(
           pht(
             'Documentation uses `%s`, but should use `%s`.',
             '@returns',
             '@return'));
       }
     }
 
+    $return = (array)$return;
+    if (count($return) > 1) {
+        $atom->addWarning(
+          pht(
+            'Documentation specifies `%s` multiple times.',
+            '@return'));
+    }
+    $return = head($return);
+
     if ($atom->getName() == '__construct' && $atom->getType() == 'method') {
       $return_spec = array(
         'doctype' => 'this',
         'docs' => '//Implicit.//',
       );
 
       if ($return) {
         $atom->addWarning(
           pht(
             'Method `%s` has explicitly documented `%s`. The `%s` method '.
             'always returns `%s`. Diviner documents this implicitly.',
             '__construct()',
             '@return',
             '__construct()',
             '$this'));
       }
     } else if ($return) {
       $split = preg_split('/(?<!,)\s+/', trim($return), 2);
       if (!empty($split[0])) {
         $type = $split[0];
       }
 
       if ($decl->getChildByIndex(1)->getTypeName() == 'n_REFERENCE') {
         $type = $type.' &';
       }
 
       if (!empty($split[1])) {
         $docs = $split[1];
       }
 
       $return_spec = array(
         'doctype' => $type,
         'docs'    => $docs,
       );
     } else {
       $return_spec = array(
         'type' => 'wild',
       );
     }
 
     $atom->setProperty('return', $return_spec);
   }
 
 }