diff --git a/.gitignore b/.gitignore
index e7997bf..f6b089b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,4 @@
 .DS_Store
-.vscode
 .idea
 vendor/
 .phpls/
diff --git a/.vscode/launch.json b/.vscode/launch.json
new file mode 100644
index 0000000..0f77709
--- /dev/null
+++ b/.vscode/launch.json
@@ -0,0 +1,29 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Listen for XDebug",
+            "type": "php",
+            "request": "launch",
+            "port": 9000
+        },
+        {
+            "name": "Launch currently open script",
+            "type": "php",
+            "request": "launch",
+            "program": "${file}",
+            "cwd": "${fileDirname}",
+            "port": 9000
+        },
+        {
+            "name": "PHPUnit",
+            "type": "php",
+            "request": "launch",
+            "program": "${workspaceRoot}/vendor/phpunit/phpunit/phpunit",
+            "cwd": "${workspaceRoot}",
+            "args": [
+                // "--filter", "CompletionTest"
+            ]
+        }
+    ]
+}
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..38150bd
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,7 @@
+// Place your settings in this file to overwrite default and user settings.
+{
+  "search.exclude": {
+    "**/validation": true,
+    "**/tests/Validation/cases": true
+  }
+}
diff --git a/README.md b/README.md
index 37800e0..432d874 100644
--- a/README.md
+++ b/README.md
@@ -170,7 +170,7 @@ Example:
 #### `--memory-limit=integer` (optional)
 Sets memory limit for language server.
 Equivalent to [memory-limit](http://php.net/manual/en/ini.core.php#ini.memory-limit) php.ini directive.
-By default there is no memory limit.
+The default is 4GB (which is way more than needed).
 
 Example:
 
diff --git a/bin/php-language-server.php b/bin/php-language-server.php
index 0e3de2a..2a2ab69 100644
--- a/bin/php-language-server.php
+++ b/bin/php-language-server.php
@@ -6,7 +6,7 @@ use Composer\{Factory, XdebugHandler};
 
 $options = getopt('', ['tcp::', 'tcp-server::', 'memory-limit::']);
 
-ini_set('memory_limit', $options['memory-limit'] ?? -1);
+ini_set('memory_limit', $options['memory-limit'] ?? '4G');
 
 foreach ([__DIR__ . '/../../../autoload.php', __DIR__ . '/../autoload.php', __DIR__ . '/../vendor/autoload.php'] as $file) {
     if (file_exists($file)) {
diff --git a/src/Protocol/PackageDescriptor.php b/src/Protocol/PackageDescriptor.php
new file mode 100644
index 0000000..e635740
--- /dev/null
+++ b/src/Protocol/PackageDescriptor.php
@@ -0,0 +1,25 @@
+<?php
+declare(strict_types = 1);
+
+namespace LanguageServer\Protocol;
+
+/**
+ * Uniquely identifies a Composer package
+ */
+class PackageDescriptor
+{
+    /**
+     * The package name
+     *
+     * @var string
+     */
+    public $name;
+
+    /**
+     * @param string $name The package name
+     */
+    public function __construct(string $name = null)
+    {
+        $this->name = $name;
+    }
+}
diff --git a/src/Protocol/SymbolDescriptor.php b/src/Protocol/SymbolDescriptor.php
index fa74bcb..4116864 100644
--- a/src/Protocol/SymbolDescriptor.php
+++ b/src/Protocol/SymbolDescriptor.php
@@ -3,7 +3,10 @@ declare(strict_types = 1);
 
 namespace LanguageServer\Protocol;
 
-class SymbolDescriptor extends SymbolInformation
+/**
+ * Uniquely identifies a symbol
+ */
+class SymbolDescriptor
 {
     /**
      * The fully qualified structural element name, a globally unique identifier for the symbol.
@@ -13,19 +16,17 @@ class SymbolDescriptor extends SymbolInformation
     public $fqsen;
 
     /**
-     * A package from the composer.lock file or the contents of the composer.json
-     * Example: https://github.com/composer/composer/blob/master/composer.lock#L10
-     * Available fields may differ
+     * Identifies the Composer package the symbol is defined in (if any)
      *
-     * @var object|null
+     * @var PackageDescriptor|null
      */
     public $package;
 
     /**
-     * @param string $fqsen   The fully qualified structural element name, a globally unique identifier for the symbol.
-     * @param object $package A package from the composer.lock file or the contents of the composer.json
+     * @param string $fqsen              The fully qualified structural element name, a globally unique identifier for the symbol.
+     * @param PackageDescriptor $package Identifies the Composer package the symbol is defined in
      */
-    public function __construct(string $fqsen = null, $package = null)
+    public function __construct(string $fqsen = null, PackageDescriptor $package = null)
     {
         $this->fqsen = $fqsen;
         $this->package = $package;
diff --git a/src/Server/TextDocument.php b/src/Server/TextDocument.php
index 2e8e4bf..5a2819e 100644
--- a/src/Server/TextDocument.php
+++ b/src/Server/TextDocument.php
@@ -8,14 +8,26 @@ use LanguageServer\{
 };
 use LanguageServer\Index\ReadableIndex;
 use LanguageServer\Protocol\{
-    FormattingOptions, Hover, Location, MarkedString, Position, Range, ReferenceContext, SymbolDescriptor, SymbolLocationInformation, TextDocumentIdentifier, TextDocumentItem, VersionedTextDocumentIdentifier
+    FormattingOptions,
+    Hover,
+    Location,
+    MarkedString,
+    Position,
+    Range,
+    ReferenceContext,
+    SymbolDescriptor,
+    PackageDescriptor,
+    SymbolLocationInformation,
+    TextDocumentIdentifier,
+    TextDocumentItem,
+    VersionedTextDocumentIdentifier
 };
 use Microsoft\PhpParser;
 use Microsoft\PhpParser\Node;
 use Sabre\Event\Promise;
 use Sabre\Uri;
 use function LanguageServer\{
-    isVendored, waitForEvent
+    isVendored, waitForEvent, getPackageName
 };
 use function Sabre\Event\coroutine;
 
@@ -368,9 +380,10 @@ class TextDocument
                 return [];
             }
             // Handle definition nodes
+            $fqn = DefinitionResolver::getDefinedFqn($node);
             while (true) {
                 if ($fqn) {
-                    $def = $this->index->getDefinition($definedFqn);
+                    $def = $this->index->getDefinition($fqn);
                 } else {
                     // Handle reference nodes
                     $def = $this->definitionResolver->resolveReferenceNodeToDefinition($node);
@@ -388,25 +401,14 @@ class TextDocument
             ) {
                 return [];
             }
-            $symbol = new SymbolDescriptor;
-            foreach (get_object_vars($def->symbolInformation) as $prop => $val) {
-                $symbol->$prop = $val;
-            }
-            $symbol->fqsen = $def->fqn;
+            // if Definition is inside a dependency, use the package name
             $packageName = getPackageName($def->symbolInformation->location->uri, $this->composerJson);
-            if ($packageName && $this->composerLock !== null) {
-                // Definition is inside a dependency
-                foreach (array_merge($this->composerLock->packages, $this->composerLock->{'packages-dev'}) as $package) {
-                    if ($package->name === $packageName) {
-                        $symbol->package = $package;
-                        break;
-                    }
-                }
-            } else if ($this->composerJson !== null) {
-                // Definition belongs to a root package
-                $symbol->package = $this->composerJson;
+            // else use the package name of the root package (if exists)
+            if (!$packageName && $this->composerJson !== null) {
+                $packageName = $this->composerJson->name;
             }
-            return [new SymbolLocationInformation($symbol, $symbol->location)];
+            $descriptor = new SymbolDescriptor($def->fqn, new PackageDescriptor($packageName));
+            return [new SymbolLocationInformation($descriptor, $def->symbolInformation->location)];
         });
     }
 }
diff --git a/src/Server/Workspace.php b/src/Server/Workspace.php
index d2f8cec..61db068 100644
--- a/src/Server/Workspace.php
+++ b/src/Server/Workspace.php
@@ -10,13 +10,15 @@ use LanguageServer\Protocol\{
     FileEvent,
     SymbolInformation,
     SymbolDescriptor,
+    PackageDescriptor,
     ReferenceInformation,
     DependencyReference,
-    Location
+    Location,
+    MessageType
 };
 use Sabre\Event\Promise;
 use function Sabre\Event\coroutine;
-use function LanguageServer\{waitForEvent, getPackageName};
+use function LanguageServer\waitForEvent;
 
 /**
  * Provides method handlers for all workspace/* methods
@@ -33,7 +35,7 @@ class Workspace
      *
      * @var ProjectIndex
      */
-    private $index;
+    private $projectIndex;
 
     /**
      * @var DependenciesIndex
@@ -57,17 +59,17 @@ class Workspace
 
     /**
      * @param LanguageClient    $client            LanguageClient instance used to signal updated results
-     * @param ProjectIndex      $index             Index that is searched on a workspace/symbol request
+     * @param ProjectIndex      $projectIndex      Index that is used to wait for full index completeness
      * @param DependenciesIndex $dependenciesIndex Index that is used on a workspace/xreferences request
      * @param DependenciesIndex $sourceIndex       Index that is used on a workspace/xreferences request
      * @param \stdClass         $composerLock      The parsed composer.lock of the project, if any
      * @param PhpDocumentLoader $documentLoader    PhpDocumentLoader instance to load documents
      */
-    public function __construct(LanguageClient $client, ProjectIndex $index, DependenciesIndex $dependenciesIndex, Index $sourceIndex, \stdClass $composerLock = null, PhpDocumentLoader $documentLoader, \stdClass $composerJson = null)
+    public function __construct(LanguageClient $client, ProjectIndex $projectIndex, DependenciesIndex $dependenciesIndex, Index $sourceIndex, \stdClass $composerLock = null, PhpDocumentLoader $documentLoader, \stdClass $composerJson = null)
     {
         $this->client = $client;
         $this->sourceIndex = $sourceIndex;
-        $this->index = $index;
+        $this->projectIndex = $projectIndex;
         $this->dependenciesIndex = $dependenciesIndex;
         $this->composerLock = $composerLock;
         $this->documentLoader = $documentLoader;
@@ -84,11 +86,11 @@ class Workspace
     {
         return coroutine(function () use ($query) {
             // Wait until indexing for definitions finished
-            if (!$this->index->isStaticComplete()) {
-                yield waitForEvent($this->index, 'static-complete');
+            if (!$this->sourceIndex->isStaticComplete()) {
+                yield waitForEvent($this->sourceIndex, 'static-complete');
             }
             $symbols = [];
-            foreach ($this->index->getDefinitions() as $fqn => $definition) {
+            foreach ($this->sourceIndex->getDefinitions() as $fqn => $definition) {
                 if ($query === '' || stripos($fqn, $query) !== false) {
                     $symbols[] = $definition->symbolInformation;
                 }
@@ -126,8 +128,8 @@ class Workspace
                 return [];
             }
             // Wait until indexing finished
-            if (!$this->index->isComplete()) {
-                yield waitForEvent($this->index, 'complete');
+            if (!$this->projectIndex->isComplete()) {
+                yield waitForEvent($this->projectIndex, 'complete');
             }
             /** Map from URI to array of referenced FQNs in dependencies */
             $refs = [];
@@ -146,38 +148,11 @@ class Workspace
             $refInfos = [];
             foreach ($refs as $uri => $fqns) {
                 foreach ($fqns as $fqn) {
-                    $def = $this->dependenciesIndex->getDefinition($fqn);
-                    $symbol = new SymbolDescriptor;
-                    $symbol->fqsen = $fqn;
-                    foreach (get_object_vars($def->symbolInformation) as $prop => $val) {
-                        $symbol->$prop = $val;
-                    }
-                    // Find out package name
-                    $packageName = getPackageName($def->symbolInformation->location->uri, $this->composerJson);
-                    foreach (array_merge($this->composerLock->packages, $this->composerLock->{'packages-dev'}) as $package) {
-                        if ($package->name === $packageName) {
-                            $symbol->package = $package;
-                            break;
-                        }
-                    }
-                    // If there was no FQSEN provided, check if query attributes match
-                    if (!isset($query->fqsen)) {
-                        $matches = true;
-                        foreach (get_object_vars($query) as $prop => $val) {
-                            if ($query->$prop != $symbol->$prop) {
-                                $matches = false;
-                                break;
-                            }
-                        }
-                        if (!$matches) {
-                            continue;
-                        }
-                    }
                     $doc = yield $this->documentLoader->getOrLoad($uri);
                     foreach ($doc->getReferenceNodesByFqn($fqn) as $node) {
                         $refInfo = new ReferenceInformation;
                         $refInfo->reference = Location::fromNode($node);
-                        $refInfo->symbol = $symbol;
+                        $refInfo->symbol = $query;
                         $refInfos[] = $refInfo;
                     }
                 }