diff --git a/src/LanguageServer.php b/src/LanguageServer.php
index 3c999f2..8fe9ec1 100644
--- a/src/LanguageServer.php
+++ b/src/LanguageServer.php
@@ -253,6 +253,7 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
             }
             if ($this->workspace === null) {
                 $this->workspace = new Server\Workspace(
+                    $this->client,
                     $this->projectIndex,
                     $dependenciesIndex,
                     $sourceIndex,
diff --git a/src/Protocol/FileEvent.php b/src/Protocol/FileEvent.php
index b4ed833..015044d 100644
--- a/src/Protocol/FileEvent.php
+++ b/src/Protocol/FileEvent.php
@@ -20,4 +20,14 @@ class FileEvent
      * @var int
      */
     public $type;
+
+    /**
+     * @param string $uri
+     * @param int $type
+     */
+    public function __construct(string $uri, int $type)
+    {
+        $this->uri = $uri;
+        $this->type = $type;
+    }
 }
diff --git a/src/Server/Workspace.php b/src/Server/Workspace.php
index b94618c..d2f8cec 100644
--- a/src/Server/Workspace.php
+++ b/src/Server/Workspace.php
@@ -5,7 +5,15 @@ namespace LanguageServer\Server;
 
 use LanguageServer\{LanguageClient, Project, PhpDocumentLoader};
 use LanguageServer\Index\{ProjectIndex, DependenciesIndex, Index};
-use LanguageServer\Protocol\{SymbolInformation, SymbolDescriptor, ReferenceInformation, DependencyReference, Location};
+use LanguageServer\Protocol\{
+    FileChangeType,
+    FileEvent,
+    SymbolInformation,
+    SymbolDescriptor,
+    ReferenceInformation,
+    DependencyReference,
+    Location
+};
 use Sabre\Event\Promise;
 use function Sabre\Event\coroutine;
 use function LanguageServer\{waitForEvent, getPackageName};
@@ -15,6 +23,11 @@ use function LanguageServer\{waitForEvent, getPackageName};
  */
 class Workspace
 {
+    /**
+     * @var LanguageClient
+     */
+    public $client;
+
     /**
      * The symbol index for the workspace
      *
@@ -43,14 +56,16 @@ class Workspace
     public $documentLoader;
 
     /**
+     * @param LanguageClient    $client            LanguageClient instance used to signal updated results
      * @param ProjectIndex      $index             Index that is searched on a workspace/symbol request
      * @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(ProjectIndex $index, DependenciesIndex $dependenciesIndex, Index $sourceIndex, \stdClass $composerLock = null, PhpDocumentLoader $documentLoader, \stdClass $composerJson = null)
+    public function __construct(LanguageClient $client, ProjectIndex $index, DependenciesIndex $dependenciesIndex, Index $sourceIndex, \stdClass $composerLock = null, PhpDocumentLoader $documentLoader, \stdClass $composerJson = null)
     {
+        $this->client = $client;
         $this->sourceIndex = $sourceIndex;
         $this->index = $index;
         $this->dependenciesIndex = $dependenciesIndex;
@@ -82,6 +97,21 @@ class Workspace
         });
     }
 
+    /**
+     * The watched files notification is sent from the client to the server when the client detects changes to files watched by the language client.
+     *
+     * @param FileEvent[] $changes
+     * @return void
+     */
+    public function didChangeWatchedFiles(array $changes)
+    {
+        foreach ($changes as $change) {
+            if ($change->type === FileChangeType::DELETED) {
+                $this->client->textDocument->publishDiagnostics($change->uri, []);
+            }
+        }
+    }
+
     /**
      * The workspace references request is sent from the client to the server to locate project-wide references to a symbol given its description / metadata.
      *
diff --git a/tests/Server/ServerTestCase.php b/tests/Server/ServerTestCase.php
index 679191f..94ba933 100644
--- a/tests/Server/ServerTestCase.php
+++ b/tests/Server/ServerTestCase.php
@@ -54,7 +54,7 @@ abstract class ServerTestCase extends TestCase
         $client               = new LanguageClient(new MockProtocolStream, new MockProtocolStream);
         $this->documentLoader = new PhpDocumentLoader(new FileSystemContentRetriever, $projectIndex, $definitionResolver);
         $this->textDocument   = new Server\TextDocument($this->documentLoader, $definitionResolver, $client, $projectIndex);
-        $this->workspace      = new Server\Workspace($projectIndex, $dependenciesIndex, $sourceIndex, null, $this->documentLoader);
+        $this->workspace      = new Server\Workspace($client, $projectIndex, $dependenciesIndex, $sourceIndex, null, $this->documentLoader);
 
         $globalSymbolsUri    = pathToUri(realpath(__DIR__ . '/../../fixtures/global_symbols.php'));
         $globalReferencesUri = pathToUri(realpath(__DIR__ . '/../../fixtures/global_references.php'));
diff --git a/tests/Server/Workspace/DidChangeWatchedFilesTest.php b/tests/Server/Workspace/DidChangeWatchedFilesTest.php
new file mode 100644
index 0000000..1074c58
--- /dev/null
+++ b/tests/Server/Workspace/DidChangeWatchedFilesTest.php
@@ -0,0 +1,41 @@
+<?php
+declare(strict_types = 1);
+
+namespace LanguageServer\Tests\Server\Workspace;
+
+use LanguageServer\ContentRetriever\FileSystemContentRetriever;
+use LanguageServer\{DefinitionResolver, LanguageClient, PhpDocumentLoader, Server};
+use LanguageServer\Index\{DependenciesIndex, Index, ProjectIndex};
+use LanguageServer\Protocol\{FileChangeType, FileEvent, Message};
+use LanguageServer\Tests\MockProtocolStream;
+use LanguageServer\Tests\Server\ServerTestCase;
+use LanguageServer\Server\Workspace;
+use Sabre\Event\Loop;
+
+class DidChangeWatchedFilesTest extends ServerTestCase
+{
+    public function testDeletingFileClearsAllDiagnostics()
+    {
+        $client = new LanguageClient(new MockProtocolStream(), $writer = new MockProtocolStream());
+        $projectIndex = new ProjectIndex($sourceIndex = new Index(), $dependenciesIndex = new DependenciesIndex());
+        $definitionResolver = new DefinitionResolver($projectIndex);
+        $loader = new PhpDocumentLoader(new FileSystemContentRetriever(), $projectIndex, $definitionResolver);
+        $workspace = new Server\Workspace($client, $projectIndex, $dependenciesIndex, $sourceIndex, null, $loader, null);
+
+        $fileEvent = new FileEvent('my uri', FileChangeType::DELETED);
+
+        $isDiagnosticsCleared = false;
+        $writer->on('message', function (Message $message) use ($fileEvent, &$isDiagnosticsCleared) {
+            if ($message->body->method === "textDocument/publishDiagnostics") {
+                $this->assertEquals($message->body->params->uri, $fileEvent->uri);
+                $this->assertEquals($message->body->params->diagnostics, []);
+                $isDiagnosticsCleared = true;
+            }
+        });
+
+        $workspace->didChangeWatchedFiles([$fileEvent]);
+        Loop\tick(true);
+
+        $this->assertTrue($isDiagnosticsCleared, "Deleting file should clear all diagnostics.");
+    }
+}