diff --git a/README.md b/README.md
index 6b93a8dc..f95d04f6 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,7 @@ This extension provides several commands in the Command Palette (<kbd>F1</kbd> o
 | `arduino.commandPath` | Path to an executable (or script) relative to `arduino.path`. The default value is `arduino_debug.exe` for windows,`Contents/MacOS/Arduino` for Mac and `arduino` for Linux, You also can use a custom launch script to run Arduino by modifying this setting. (Requires a restart after change) Example: `run-arduino.bat` for Windows, `Contents/MacOS/run-arduino.sh` for Mac and `bin/run-arduino.sh` for Linux. |
 | `arduino.additionalUrls` | Additional Boards Manager URLs for 3rd party packages. You can have multiple URLs in one string with a comma(`,`) as separator, or have a string array. The default value is empty. |
 | `arduino.logLevel` | CLI output log level. Could be info or verbose. The default value is `"info"`. |
+| `arduino.allowPDEFiletype` | Allow the VSCode Arduino extension to open .pde files from pre-1.0.0 versions of Ardiuno. Note that this will break Processing code. Default value is `false`. | 
 | `arduino.enableUSBDetection` | Enable/disable USB detection from the VSCode Arduino extension. The default value is `true`. When your device is plugged in to your computer, it will pop up a message "`Detected board ****, Would you like to switch to this board type`". After clicking the `Yes` button, it will automatically detect which serial port (COM) is connected a USB device. If your device does not support this feature, please provide us with the PID/VID of your device; the code format is defined in `misc/usbmapping.json`.To learn more about how to list the vid/pid, use the following tools: https://github.com/EmergingTechnologyAdvisors/node-serialport `npm install -g serialport` `serialport-list -f jsonline`|
 | `arduino.disableTestingOpen` | Enable/disable automatic sending of a test message to the serial port for checking the open status. The default value is `false` (a test message will be sent). |
 | `arduino.skipHeaderProvider` | Enable/disable the extension providing completion items for headers. This functionality is included in newer versions of the C++ extension. The default value is `false`.|
@@ -74,6 +75,7 @@ The following Visual Studio Code settings are available for the Arduino extensio
     "arduino.path": "C:/Program Files (x86)/Arduino",
     "arduino.commandPath": "arduino_debug.exe",
     "arduino.logLevel": "info",
+    "arduino.allowPDEFiletype": false, 
     "arduino.enableUSBDetection": true,
     "arduino.disableTestingOpen": false,
     "arduino.skipHeaderProvider": false,
diff --git a/package.json b/package.json
index 1ca05405..08c42db3 100644
--- a/package.json
+++ b/package.json
@@ -465,6 +465,11 @@
             "verbose"
           ]
         },
+        "arduino.openPDEFiletype":{
+          "type":"boolean",
+          "default":false,
+          "description": "Allow VSCode Arduino to open PDE sketches, from pre-1.0.0 versions of Arduino"
+        },
         "arduino.enableUSBDetection": {
           "type": "boolean",
           "default": true
@@ -505,8 +510,7 @@
       {
         "id": "cpp",
         "extensions": [
-          ".ino",
-          ".pde"
+          ".ino"
         ]
       }
     ],
diff --git a/src/arduino/vscodeSettings.ts b/src/arduino/vscodeSettings.ts
index a2fce5ab..f66e268b 100644
--- a/src/arduino/vscodeSettings.ts
+++ b/src/arduino/vscodeSettings.ts
@@ -9,7 +9,8 @@ const configKeys = {
     ADDITIONAL_URLS: "arduino.additionalUrls",
     LOG_LEVEL: "arduino.logLevel",
     AUTO_UPDATE_INDEX_FILES: "arduino.autoUpdateIndexFiles",
-    ENABLE_USB_DETECTOIN: "arduino.enableUSBDetection",
+    ALLOW_PDE_FILETYPE: "arduino.allowPDEFiletype",
+    ENABLE_USB_DETECTION: "arduino.enableUSBDetection",
     DISABLE_TESTING_OPEN: "arduino.disableTestingOpen",
     IGNORE_BOARDS: "arduino.ignoreBoards",
     SKIP_HEADER_PROVIDER: "arduino.skipHeaderProvider",
@@ -21,6 +22,7 @@ export interface IVscodeSettings {
     commandPath: string;
     additionalUrls: string | string[];
     logLevel: string;
+    allowPDEFiletype: boolean;
     enableUSBDetection: boolean;
     disableTestingOpen: boolean;
     ignoreBoards: string[];
@@ -57,8 +59,12 @@ export class VscodeSettings implements IVscodeSettings {
         return this.getConfigValue<string>(configKeys.LOG_LEVEL) || "info";
     }
 
+    public get allowPDEFiletype(): boolean {
+        return this.getConfigValue<boolean>(configKeys.ALLOW_PDE_FILETYPE);
+    }
+
     public get enableUSBDetection(): boolean {
-        return this.getConfigValue<boolean>(configKeys.ENABLE_USB_DETECTOIN);
+        return this.getConfigValue<boolean>(configKeys.ENABLE_USB_DETECTION);
     }
 
     public get disableTestingOpen(): boolean {
diff --git a/src/extension.ts b/src/extension.ts
index adf3ffb7..8347e873 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -9,6 +9,7 @@ import * as constants from "./common/constants";
 
 import { ArduinoContentProvider } from "./arduino/arduinoContentProvider";
 import { IBoard } from "./arduino/package";
+import { VscodeSettings } from "./arduino/vscodeSettings";
 import ArduinoActivator from "./arduinoActivator";
 import ArduinoContext from "./arduinoContext";
 import {
@@ -43,7 +44,7 @@ export async function activate(context: vscode.ExtensionContext) {
                 "the arduino extension might not work appropriately.");
         }
     }
-
+    const vscodeSettings = VscodeSettings.getInstance();
     const deviceContext = DeviceContext.getInstance();
     deviceContext.extensionPath = context.extensionPath;
     context.subscriptions.push(deviceContext);
@@ -329,29 +330,31 @@ export async function activate(context: vscode.ExtensionContext) {
         }
     });
 
-    vscode.workspace.onDidOpenTextDocument(async (document) => {
-        if (/\.pde$/.test(document.uri.fsPath)) {
-            const newFsName = document.uri.fsPath.replace(/\.pde$/, ".ino");
-            await vscode.commands.executeCommand("workbench.action.closeActiveEditor");
-            fs.renameSync(document.uri.fsPath, newFsName);
-            await vscode.commands.executeCommand("vscode.open", vscode.Uri.file(newFsName));
-        }
-    });
+    const allowPDEFiletype = vscodeSettings.allowPDEFiletype;
 
-    vscode.window.onDidChangeActiveTextEditor(async (editor) => {
-        if (!editor) {
-            return;
-        }
-
-        const document = editor.document;
-        if (/\.pde$/.test(document.uri.fsPath)) {
-            const newFsName = document.uri.fsPath.replace(/\.pde$/, ".ino");
-            await vscode.commands.executeCommand("workbench.action.closeActiveEditor");
-            fs.renameSync(document.uri.fsPath, newFsName);
-            await vscode.commands.executeCommand("vscode.open", vscode.Uri.file(newFsName));
-        }
-    });
+    if (allowPDEFiletype) {
+        vscode.workspace.onDidOpenTextDocument(async (document) => {
+            if (/\.pde$/.test(document.uri.fsPath)) {
+                const newFsName = document.uri.fsPath.replace(/\.pde$/, ".ino");
+                await vscode.commands.executeCommand("workbench.action.closeActiveEditor");
+                fs.renameSync(document.uri.fsPath, newFsName);
+                await vscode.commands.executeCommand("vscode.open", vscode.Uri.file(newFsName));
+            }
+        });
 
+        vscode.window.onDidChangeActiveTextEditor(async (editor) => {
+            if (!editor) {
+                return;
+            }
+            const document = editor.document;
+            if (/\.pde$/.test(document.uri.fsPath)) {
+                const newFsName = document.uri.fsPath.replace(/\.pde$/, ".ino");
+                await vscode.commands.executeCommand("workbench.action.closeActiveEditor");
+                fs.renameSync(document.uri.fsPath, newFsName);
+                await vscode.commands.executeCommand("vscode.open", vscode.Uri.file(newFsName));
+            }
+        });
+    }
     Logger.traceUserData("end-activate-extension", { correlationId: activeGuid });
 }