diff --git a/core/xml.js b/core/xml.js
index 0120ed279..45b3e0ca6 100644
--- a/core/xml.js
+++ b/core/xml.js
@@ -77,10 +77,20 @@ Blockly.Xml.variablesToDom = function(variableList) {
  * @return {!Element} Tree of XML elements.
  */
 Blockly.Xml.blockToDomWithXY = function(block, opt_noId) {
+  if (block.isInsertionMarker()) {  // Skip over insertion markers.
+    block = block.getChildren(false)[0];
+    if (!block) {
+      // Disappears when appended. Cast to ANY b/c DocumentFragment -> Element
+      // is invalid. We have to cast to ANY in between.
+      return /** @type{?} */ (new DocumentFragment());
+    }
+  }
+
   var width;  // Not used in LTR.
   if (block.workspace.RTL) {
     width = block.workspace.getWidth();
   }
+
   var element = Blockly.Xml.blockToDom(block, opt_noId);
   var xy = block.getRelativeToSurfaceXY();
   element.setAttribute('x',
@@ -131,6 +141,19 @@ Blockly.Xml.allFieldsToDom_ = function(block, element) {
  * @return {!Element} Tree of XML elements.
  */
 Blockly.Xml.blockToDom = function(block, opt_noId) {
+  // Skip over insertion markers.
+  if (block.isInsertionMarker()) {
+    var child = block.getChildren(false)[0];
+    if (child) {
+      return Blockly.Xml.blockToDom(child);
+    } else {
+      // Disappears when appended. Cast to ANY b/c DocumentFragment -> Element
+      // is invalid. We have to cast to ANY in between.
+      return /** @type{?} */ (new DocumentFragment());
+    }
+  }
+
+
   var element =
       Blockly.utils.xml.createElement(block.isShadow() ? 'shadow' : 'block');
   element.setAttribute('type', block.type);
@@ -186,8 +209,11 @@ Blockly.Xml.blockToDom = function(block, opt_noId) {
         container.appendChild(Blockly.Xml.cloneShadow_(shadow, opt_noId));
       }
       if (childBlock) {
-        container.appendChild(Blockly.Xml.blockToDom(childBlock, opt_noId));
-        empty = false;
+        var elem = Blockly.Xml.blockToDom(childBlock, opt_noId);
+        if (elem.nodeType == Blockly.utils.dom.NodeType.ELEMENT_NODE) {
+          container.appendChild(elem);
+          empty = false;
+        }
       }
     }
     container.setAttribute('name', input.name);
@@ -217,9 +243,12 @@ Blockly.Xml.blockToDom = function(block, opt_noId) {
 
   var nextBlock = block.getNextBlock();
   if (nextBlock) {
-    var container = Blockly.utils.xml.createElement('next');
-    container.appendChild(Blockly.Xml.blockToDom(nextBlock, opt_noId));
-    element.appendChild(container);
+    var elem = Blockly.Xml.blockToDom(nextBlock, opt_noId);
+    if (elem.nodeType == Blockly.utils.dom.NodeType.ELEMENT_NODE) {
+      var container = Blockly.utils.xml.createElement('next');
+      container.appendChild(elem);
+      element.appendChild(container);
+    }
   }
   var shadow = block.nextConnection && block.nextConnection.getShadowDom();
   if (shadow && (!nextBlock || !nextBlock.isShadow())) {
diff --git a/tests/mocha/insertion_marker_test.js b/tests/mocha/insertion_marker_test.js
index fd3a5bc6b..afe34f2c7 100644
--- a/tests/mocha/insertion_marker_test.js
+++ b/tests/mocha/insertion_marker_test.js
@@ -6,7 +6,7 @@
 
 suite('InsertionMarkers', function() {
   setup(function() {
-    this.workspace = new Blockly.Workspace();
+    this.workspace = Blockly.inject('blocklyDiv', {});
     Blockly.defineBlocksWithJsonArray([
       {
         "type": "stack_block",
@@ -200,4 +200,187 @@ suite('InsertionMarkers', function() {
       this.assertGen(xml, 'stack[a];\n');
     });
   });
+  suite('Serialization', function() {
+    setup(function() {
+      this.assertXml = function(xml, expectXml) {
+        Blockly.Xml.domToWorkspace(xml, this.workspace);
+        var block = this.workspace.getBlockById('insertion');
+        block.setInsertionMarker(true);
+        var xml = Blockly.Xml.workspaceToDom(this.workspace);
+        Blockly.Xml.domToWorkspace(xml, this.workspace);
+        xml = Blockly.Xml.domToText(xml);
+        chai.assert.equal(xml, expectXml);
+      };
+    });
+    teardown(function() {
+      delete this.assertXml;
+    });
+    test('Marker Surrounds', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="statement_block" id="insertion" x="20" y="20">' +
+          '    <statement name="STATEMENT">' +
+          '      <block type="statement_block" id="a"/>' +
+          '    </statement>' +
+          '  </block>' +
+          '</xml>');
+      // Note how the x and y are not 20, they are slightly lower and end-er
+      // because these are the coords of the wrapped block.
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="statement_block" id="a" x="41" y="31"></block>' +
+          '</xml>');
+    });
+    test('Marker Enclosed', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="statement_block" id="a" x="20" y="20">' +
+          '    <statement name="STATEMENT">' +
+          '      <block type="statement_block" id="insertion"/>' +
+          '    </statement>' +
+          '  </block>' +
+          '</xml>');
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="statement_block" id="a" x="20" y="20"></block>' +
+          '</xml>');
+    });
+    test('Marker Enclosed and Surrounds', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="statement_block" id="a" x="20" y="20">' +
+          '    <statement name="STATEMENT">' +
+          '      <block type="statement_block" id="insertion">' +
+          '        <statement name="STATEMENT">' +
+          '          <block type="statement_block" id="b"/>' +
+          '        </statement>' +
+          '      </block>' +
+          '    </statement>' +
+          '  </block>' +
+          '</xml>');
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="statement_block" id="a" x="20" y="20">' +
+          '<statement name="STATEMENT">' +
+          '<block type="statement_block" id="b"></block>' +
+          '</statement>' +
+          '</block>' +
+          '</xml>');
+    });
+    test('Marker Prev', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="stack_block" id="insertion" x="20" y="20">' +
+          '    <next>' +
+          '      <block type="stack_block" id="a"/>' +
+          '    </next>' +
+          '  </block>' +
+          '</xml>');
+      // Note how the y coord is not at 20, it is lower. This is because these
+      // are the coords of the next block.
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="stack_block" id="a" x="20" y="46"></block>' +
+          '</xml>');
+    });
+    test('Marker Next', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="stack_block" id="a" x="20" y="20">' +
+          '    <next>' +
+          '      <block type="stack_block" id="insertion"/>' +
+          '    </next>' +
+          '  </block>' +
+          '</xml>');
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="stack_block" id="a" x="20" y="20"></block>' +
+          '</xml>');
+    });
+    test('Marker Middle of Stack', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="stack_block" id="a" x="20" y="20">' +
+          '    <next>' +
+          '      <block type="stack_block" id="insertion">' +
+          '        <next>' +
+          '          <block type="stack_block" id="b"/>' +
+          '        </next>' +
+          '      </block>' +
+          '    </next>' +
+          '  </block>' +
+          '</xml>');
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="stack_block" id="a" x="20" y="20">' +
+          '<next>' +
+          '<block type="stack_block" id="b"></block>' +
+          '</next>' +
+          '</block>' +
+          '</xml>');
+    });
+    test('Marker On Output', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="row_block" id="insertion" x="20" y="20">' +
+          '    <value name="INPUT">' +
+          '      <block type="row_block" id="a"/>' +
+          '    </value>' +
+          '  </block>' +
+          '</xml>');
+      // Note how the x value is not at 20. This is because these are the coords
+      // of the wrapped block.
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="row_block" id="a" x="41" y="20"></block>' +
+          '</xml>');
+    });
+    test('Marker On Input', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="row_block" id="a" x="20" y="20">' +
+          '    <value name="INPUT">' +
+          '      <block type="row_block" id="insertion"/>' +
+          '    </value>' +
+          '  </block>' +
+          '</xml>');
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="row_block" id="a" x="20" y="20"></block>' +
+          '</xml>');
+    });
+    test('Marker Middle of Row', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="row_block" id="a" x="20" y="20">' +
+          '    <value name="INPUT">' +
+          '      <block type="row_block" id="insertion">' +
+          '        <value name="INPUT">' +
+          '          <block type="row_block" id="b"/>' +
+          '        </value>' +
+          '      </block>' +
+          '    </value>' +
+          '  </block>' +
+          '</xml>');
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="row_block" id="a" x="20" y="20">' +
+          '<value name="INPUT">' +
+          '<block type="row_block" id="b"></block>' +
+          '</value>' +
+          '</block>' +
+          '</xml>');
+    });
+    test('Marker Detatched', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="stack_block" id="insertion"/>' +
+          '  <block type="stack_block" id="a" x="20" y="20"/>' +
+          '</xml>');
+      this.assertXml(xml,
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '<block type="stack_block" id="a" x="20" y="20"></block>' +
+          '</xml>');
+    });
+  });
 });