diff --git a/package.json b/package.json
index 02f5f88..7085f87 100644
--- a/package.json
+++ b/package.json
@@ -85,7 +85,8 @@
           ".c",
           ".cpp",
           ".h",
-          ".hpp"
+          ".hpp",
+          ".pde"
         ],
         "configuration": "./languages/ino.language-configuration.json"
       }
diff --git a/src/extension.ts b/src/extension.ts
index ad9ef3c..c34d65e 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -191,7 +191,7 @@ async function buildLanguageClient(config: LanguageServerConfig): Promise<Langua
         },
         {
             initializationOptions: {},
-            documentSelector: ['ino', 'c', 'cpp', 'h', 'hpp'],
+            documentSelector: ['ino', 'c', 'cpp', 'h', 'hpp', 'pde'],
             uriConverters: {
                 code2Protocol: (uri: vscode.Uri): string => (uri.scheme ? uri : uri.with({ scheme: 'file' })).toString(),
                 protocol2Code: (uri: string) => vscode.Uri.parse(uri)