diff --git a/src/Psalm/Internal/Codebase/Analyzer.php b/src/Psalm/Internal/Codebase/Analyzer.php
index ea0806383..2688c3229 100644
--- a/src/Psalm/Internal/Codebase/Analyzer.php
+++ b/src/Psalm/Internal/Codebase/Analyzer.php
@@ -576,6 +576,11 @@ class Analyzer
             $i = 0;
 
             foreach ($this->files_to_analyze as $file_path => $_) {
+                // Remove all current maps for the file, so new analysis doesn't
+                // only append to existing data.
+                unset($this->reference_map[$file_path]);
+                unset($this->type_map[$file_path]);
+                unset($this->argument_map[$file_path]);
                 $analysis_worker($i, $file_path);
                 ++$i;
 
diff --git a/tests/FileUpdates/AnalyzedMethodTest.php b/tests/FileUpdates/AnalyzedMethodTest.php
index 682d18837..2736b4244 100644
--- a/tests/FileUpdates/AnalyzedMethodTest.php
+++ b/tests/FileUpdates/AnalyzedMethodTest.php
@@ -1318,4 +1318,40 @@ class AnalyzedMethodTest extends \Psalm\Tests\TestCase
             ],
         ];
     }
+
+    public function testFileMapsUpdated(): void
+    {
+        $codebase = $this->project_analyzer->getCodebase();
+
+        $config = $codebase->config;
+        $config->throw_exception = false;
+
+        $this->file_provider->registerFile('somefile.php', '
+            <?php
+
+            function foo() : void {
+            }
+
+            foo();
+        ');
+
+        $codebase->addFilesToAnalyze(['somefile.php' => 'somefile.php']);
+        $codebase->scanFiles();
+        $codebase->analyzer->analyzeFiles($this->project_analyzer, 1, false);
+
+        $maps = $codebase->analyzer->getMapsForFile('somefile.php');
+
+        $this->assertNotEmpty($maps[0]);
+
+        $this->file_provider->setOpenContents('somefile.php', '');
+
+        $codebase->reloadFiles($this->project_analyzer, ['somefile.php']);
+        $codebase->analyzer->analyzeFiles($this->project_analyzer, 1, false);
+
+        $updated_maps = $codebase->analyzer->getMapsForFile('somefile.php');
+
+        $this->assertSame([], $updated_maps[0]);
+        $this->assertSame([], $updated_maps[1]);
+        $this->assertSame([], $updated_maps[2]);
+    }
 }
diff --git a/tests/Internal/Provider/FakeFileProvider.php b/tests/Internal/Provider/FakeFileProvider.php
index 94b403a21..45cac5a8a 100644
--- a/tests/Internal/Provider/FakeFileProvider.php
+++ b/tests/Internal/Provider/FakeFileProvider.php
@@ -40,6 +40,13 @@ class FakeFileProvider extends \Psalm\Internal\Provider\FileProvider
         $this->fake_files[$file_path] = $file_contents;
     }
 
+    public function setOpenContents(string $file_path, string $file_contents): void
+    {
+        if (isset($this->fake_files[strtolower($file_path)])) {
+            $this->fake_files[strtolower($file_path)] = $file_contents;
+        }
+    }
+
     public function getModifiedTime(string $file_path): int
     {
         if (isset($this->fake_file_times[$file_path])) {
diff --git a/tests/LanguageServer/FileMapTest.php b/tests/LanguageServer/FileMapTest.php
new file mode 100644
index 000000000..5166da894
--- /dev/null
+++ b/tests/LanguageServer/FileMapTest.php
@@ -0,0 +1,103 @@
+<?php
+namespace Psalm\Tests\LanguageServer;
+
+use LanguageServerProtocol\Position;
+use Psalm\Context;
+use Psalm\Internal\Analyzer\ProjectAnalyzer;
+use Psalm\Internal\Provider\Providers;
+use Psalm\Tests\Internal\Provider;
+use Psalm\Tests\TestConfig;
+
+class FileMapTest extends \Psalm\Tests\TestCase
+{
+    public function setUp() : void
+    {
+        parent::setUp();
+
+        $this->file_provider = new \Psalm\Tests\Internal\Provider\FakeFileProvider();
+
+        $config = new TestConfig();
+
+        $providers = new Providers(
+            $this->file_provider,
+            new \Psalm\Tests\Internal\Provider\ParserInstanceCacheProvider(),
+            null,
+            null,
+            new Provider\FakeFileReferenceCacheProvider(),
+            new \Psalm\Tests\Internal\Provider\ProjectCacheProvider()
+        );
+
+        $this->project_analyzer = new ProjectAnalyzer(
+            $config,
+            $providers
+        );
+        $this->project_analyzer->setPhpVersion('7.3');
+        $this->project_analyzer->getCodebase()->store_node_types = true;
+    }
+
+    public function testMapIsUpdatedOnReloadFiles(): void
+    {
+        $codebase = $this->project_analyzer->getCodebase();
+        $config = $codebase->config;
+        $config->throw_exception = false;
+
+        $this->addFile(
+            'somefile.php',
+            '<?php
+                class A {
+                    function __construct( string $var ) {
+                    }
+                }
+                $a = new A( "foo" );'
+        );
+
+        $codebase->file_provider->openFile('somefile.php');
+        $codebase->scanFiles();
+        $this->analyzeFile('somefile.php', new Context());
+        [ $type_map ] = $codebase->analyzer->getMapsForFile('somefile.php');
+
+        $this->assertTrue(!empty($type_map));
+
+        $codebase->file_provider->setOpenContents('somefile.php', '');
+        $codebase->reloadFiles($this->project_analyzer, ['somefile.php']);
+        [ $type_map ] = $codebase->analyzer->getMapsForFile('somefile.php');
+
+        $this->assertSame([], $type_map);
+    }
+
+    public function testGetTypeMap(): void
+    {
+        $codebase = $this->project_analyzer->getCodebase();
+        $config = $codebase->config;
+        $config->throw_exception = false;
+
+        $this->addFile(
+            'somefile.php',
+            '<?php
+                class A {
+                    function __construct( string $var ) {
+                    }
+                }
+                $a = new A( "foo" );'
+        );
+
+        $codebase->file_provider->openFile('somefile.php');
+        $codebase->scanFiles();
+        $this->analyzeFile('somefile.php', new Context());
+        [ $type_map ] = $codebase->analyzer->getMapsForFile('somefile.php');
+
+        $this->assertSame(
+            [
+                155 => [
+                    156,
+                    'A',
+                ],
+                146 => [
+                    148,
+                    '146-147:A',
+                ],
+            ],
+            $type_map
+        );
+    }
+}