diff --git a/README.md b/README.md
index 9333e528..ebf9042e 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,9 @@ Xterm.js is used in several world-class applications to provide great terminal e
 - [**JupyterLab**](https://github.com/jupyterlab/jupyterlab): An extensible 
 computational environment for Jupyter, supporting interactive data science and scientific computing across all programming languages.
 - [**Script Runner**](https://github.com/ioquatix/script-runner): Run scripts (or a shell) in Atom.
+- [**Whack Whack Terminal**](https://github.com/Microsoft/WhackWhackTerminal): Terminal emulator for Visual Studio 2017.
+- [**VTerm**](https://github.com/vterm/vterm): Extensible terminal emulator based on Electron and React.
+
 
 Do you use xterm.js in your application as well? Please [open a Pull Request](https://github.com/sourcelair/xterm.js/pulls) to include it here. We would love to have it in our list.
 
diff --git a/src/addons/attach/attach.js b/src/addons/attach/attach.js
index c2a7989b..2e110624 100644
--- a/src/addons/attach/attach.js
+++ b/src/addons/attach/attach.js
@@ -66,6 +66,10 @@
     };
 
     term._sendData = function (data) {
+      if (socket.readyState !== 1) {
+        return;
+      }
+
       socket.send(data);
     };