diff --git a/core/inject.js b/core/inject.js
index 57d2a13b4..65a54332e 100644
--- a/core/inject.js
+++ b/core/inject.js
@@ -420,6 +420,11 @@ Blockly.init_ = function(mainWorkspace) {
  */
 Blockly.inject.bindDocumentEvents_ = function() {
   if (!Blockly.documentEventsBound_) {
+    document.addEventListener('mouseup', function() {
+      Blockly.hideChaff();
+      Blockly.Touch.clearTouchIdentifier();  // Don't block future drags.
+    }, false);
+
     Blockly.bindEventWithChecks_(document, 'scroll', null, function() {
       var workspaces = Blockly.Workspace.getAll();
       for (var i = 0, workspace; workspace = workspaces[i]; i++) {