diff --git a/core/block_svg.js b/core/block_svg.js
index 7bdccb58e..d376a9272 100644
--- a/core/block_svg.js
+++ b/core/block_svg.js
@@ -529,7 +529,6 @@ Blockly.BlockSvg.prototype.onMouseDown_ = function(e) {
     e.stopPropagation();
     return;
   }
-  Blockly.setPageSelectable(false);
   this.workspace.markFocused();
   // Update Blockly's knowledge of its own location.
   Blockly.svgResize(this.workspace);
@@ -574,6 +573,7 @@ Blockly.BlockSvg.prototype.onMouseDown_ = function(e) {
   }
   // This event has been handled.  No need to bubble up to the document.
   e.stopPropagation();
+  e.preventDefault();
 };
 
 /**
@@ -589,7 +589,6 @@ Blockly.BlockSvg.prototype.onMouseUp_ = function(e) {
     Blockly.Events.fire(
         new Blockly.Events.Ui(this, 'click', undefined, undefined));
   }
-  Blockly.setPageSelectable(true);
   Blockly.terminateDrag_();
   if (Blockly.selected && Blockly.highlightedConnection_) {
     // Connect two blocks together.
@@ -910,6 +909,7 @@ Blockly.BlockSvg.prototype.onMouseMove_ = function(e) {
   }
   // This event has been handled.  No need to bubble up to the document.
   e.stopPropagation();
+  e.preventDefault();
 };
 
 /**
diff --git a/core/blockly.js b/core/blockly.js
index 0536332d8..beb2d8eb1 100644
--- a/core/blockly.js
+++ b/core/blockly.js
@@ -196,7 +196,6 @@ Blockly.onMouseUp_ = function(e) {
   var workspace = Blockly.getMainWorkspace();
   Blockly.Css.setCursor(Blockly.Css.Cursor.OPEN);
   workspace.isScrolling = false;
-  Blockly.setPageSelectable(true);
   // Unbind the touch event if it exists.
   if (Blockly.onTouchUpWrapper_) {
     Blockly.unbindEvent_(Blockly.onTouchUpWrapper_);
@@ -239,6 +238,7 @@ Blockly.onMouseMove_ = function(e) {
       Blockly.longStop_();
     }
     e.stopPropagation();
+    e.preventDefault();
   }
 };
 
diff --git a/core/css.js b/core/css.js
index 7e6f8be93..f1cafb0a9 100644
--- a/core/css.js
+++ b/core/css.js
@@ -143,13 +143,6 @@ Blockly.Css.CONTENT = [
     'z-index: 999;',
   '}',
 
-  '.blocklyNonSelectable {',
-    'user-select: none;',
-    '-moz-user-select: none;',
-    '-webkit-user-select: none;',
-    '-ms-user-select: none;',
-  '}',
-
   '.blocklyTooltipDiv {',
     'background-color: #ffffc7;',
     'border: 1px solid #ddc;',
diff --git a/core/scrollbar.js b/core/scrollbar.js
index df01000c6..d2c70d722 100644
--- a/core/scrollbar.js
+++ b/core/scrollbar.js
@@ -446,6 +446,7 @@ Blockly.Scrollbar.prototype.onMouseDownBar_ = function(e) {
                              this.constrainKnob_(knobValue));
   this.onScroll_();
   e.stopPropagation();
+  e.preventDefault();
 };
 
 /**
@@ -462,7 +463,6 @@ Blockly.Scrollbar.prototype.onMouseDownKnob_ = function(e) {
     e.stopPropagation();
     return;
   }
-  Blockly.setPageSelectable(false);
   // Look up the current translation and record it.
   this.startDragKnob = parseFloat(
       this.svgKnob_.getAttribute(this.horizontal_ ? 'x' : 'y'));
@@ -473,6 +473,7 @@ Blockly.Scrollbar.prototype.onMouseDownKnob_ = function(e) {
   Blockly.Scrollbar.onMouseMoveWrapper_ = Blockly.bindEvent_(document,
       'mousemove', this, this.onMouseMoveKnob_);
   e.stopPropagation();
+  e.preventDefault();
 };
 
 /**
@@ -495,7 +496,6 @@ Blockly.Scrollbar.prototype.onMouseMoveKnob_ = function(e) {
  * @private
  */
 Blockly.Scrollbar.prototype.onMouseUpKnob_ = function() {
-  Blockly.setPageSelectable(true);
   Blockly.hideChaff(true);
   if (Blockly.Scrollbar.onMouseUpWrapper_) {
     Blockly.unbindEvent_(Blockly.Scrollbar.onMouseUpWrapper_);
diff --git a/core/utils.js b/core/utils.js
index 08961e235..1a0fba1b6 100644
--- a/core/utils.js
+++ b/core/utils.js
@@ -289,19 +289,6 @@ Blockly.createSvgElement = function(name, attrs, parent, opt_workspace) {
   return e;
 };
 
-/**
- * Set css classes to allow/disallow the browser from selecting/highlighting
- * text, etc. on the page.
- * @param {boolean} selectable Whether elements on the page can be selected.
- */
-Blockly.setPageSelectable = function(selectable) {
-  if (selectable) {
-    Blockly.removeClass_(document.body, 'blocklyNonSelectable');
-  } else {
-    Blockly.addClass_(document.body, 'blocklyNonSelectable');
-  }
-};
-
 /**
  * Is this event a right-click?
  * @param {!Event} e Mouse event.
diff --git a/core/workspace_svg.js b/core/workspace_svg.js
index 3c62acac1..294dd7de0 100644
--- a/core/workspace_svg.js
+++ b/core/workspace_svg.js
@@ -564,7 +564,6 @@ Blockly.WorkspaceSvg.prototype.isDeleteArea = function(e) {
  */
 Blockly.WorkspaceSvg.prototype.onMouseDown_ = function(e) {
   this.markFocused();
-  Blockly.setPageSelectable(false);
   if (Blockly.isTargetInput_(e)) {
     return;
   }
@@ -607,6 +606,7 @@ Blockly.WorkspaceSvg.prototype.onMouseDown_ = function(e) {
   }
   // This event has been handled.  No need to bubble up to the document.
   e.stopPropagation();
+  e.preventDefault();
 };
 
 /**