diff --git a/core/trashcan.js b/core/trashcan.js
index 459d7ba4b..7fbb79178 100644
--- a/core/trashcan.js
+++ b/core/trashcan.js
@@ -313,9 +313,13 @@ Blockly.Trashcan.prototype.createDom = function() {
   this.svgLid_.setAttributeNS(Blockly.utils.dom.XLINK_NS, 'xlink:href',
       this.workspace_.options.pathToMedia + Blockly.SPRITE.url);
 
-  Blockly.bindEventWithChecks_(this.svgGroup_, 'mouseup', this, this.click);
   // bindEventWithChecks_ quashes events too aggressively. See:
   // https://groups.google.com/forum/#!topic/blockly/QF4yB9Wx00s
+  // Using bindEventWithChecks_ for blocking mousedown causes issue in mobile.
+  // See #4303
+  Blockly.bindEvent_(
+      this.svgGroup_, 'mousedown', this, this.blockMouseDownWhenOpenable_);
+  Blockly.bindEvent_(this.svgGroup_, 'mouseup', this, this.click);
   // Bind to body instead of this.svgGroup_ so that we don't get lid jitters
   Blockly.bindEvent_(body, 'mouseover', this, this.mouseOver_);
   Blockly.bindEvent_(body, 'mouseout', this, this.mouseOut_);
@@ -566,6 +570,17 @@ Blockly.Trashcan.prototype.fireUiEvent_ = function(trashcanOpen) {
   Blockly.Events.fire(uiEvent);
 };
 
+/**
+ * Prevents a workspace scroll and click event if the trashcan has blocks.
+ * @param {!Event} e A mouse down event.
+ * @private
+ */
+Blockly.Trashcan.prototype.blockMouseDownWhenOpenable_ = function(e) {
+  if (!this.contentsIsOpen() && this.hasContents_()) {
+    e.stopPropagation();  // Don't start a workspace scroll.
+  }
+};
+
 /**
  * Indicate that the trashcan can be clicked (by opening it) if it has blocks.
  * @private