diff --git a/core/serialization/blocks.js b/core/serialization/blocks.js
index 4267c295f3f..60a54021a4b 100644
--- a/core/serialization/blocks.js
+++ b/core/serialization/blocks.js
@@ -20,6 +20,7 @@ const Connection = goog.requireType('Blockly.Connection');
 const Events = goog.require('Blockly.Events');
 const {MissingBlockType, MissingConnection, BadConnectionCheck} =
     goog.require('Blockly.serialization.exceptions');
+const Size = goog.require('Blockly.utils.Size');
 // eslint-disable-next-line no-unused-vars
 const Workspace = goog.requireType('Blockly.Workspace');
 const Xml = goog.require('Blockly.Xml');
@@ -54,6 +55,7 @@ exports.ConnectionState = ConnectionState;
  *     inline: (boolean|undefined),
  *     data: (string|undefined),
  *     extra-state: *,
+ *     icons: (!Object<string, *>|undefined),
  *     fields: (!Object<string, *>|undefined),
  *     inputs: (!Object<string, !ConnectionState>|undefined),
  *     next: (!ConnectionState|undefined)
@@ -99,6 +101,7 @@ const save = function(
   }
   saveAttributes(block, state);
   saveExtraState(block, state);
+  saveIcons(block, state);
   saveFields(block, state);
   if (addInputBlocks) {
     saveInputBlocks(block, state);
@@ -171,6 +174,25 @@ const saveExtraState = function(block, state) {
   }
 };
 
+/**
+ * Adds the state of all of the icons on the block to the given state object.
+ * @param {!Block} block The block to serialize the icon state of.
+ * @param {!State} state The state object to append to.
+ */
+const saveIcons = function(block, state) {
+  // TODO(#2105): Remove this logic and put it in the icon.
+  if (block.getCommentText()) {
+    state['icons'] = {
+      'comment': {
+        'text': block.getCommentText(),
+        'pinned': block.commentModel.pinned,
+        'height': Math.round(block.commentModel.size.height),
+        'width': Math.round(block.commentModel.size.width),
+      }
+    };
+  }
+};
+
 /**
  * Adds the state of all of the fields on the block to the given state object.
  * @param {!Block} block The block to serialize the field state of.
@@ -178,7 +200,7 @@ const saveExtraState = function(block, state) {
  */
 const saveFields = function(block, state) {
   let hasFieldState = false;
-  let fields = Object.create(null);
+  const fields = Object.create(null);
   for (let i = 0; i < block.inputList.length; i++) {
     const input = block.inputList[i];
     for (let j = 0; j < input.fieldRow.length; j++) {
@@ -322,7 +344,7 @@ const loadInternal = function(state, workspace, parentConnection = undefined) {
   loadAttributes(block, state);
   loadExtraState(block, state);
   tryToConnectParent(parentConnection, block, state);
-  // loadIcons(block, state);
+  loadIcons(block, state);
   loadFields(block, state);
   loadInputBlocks(block, state);
   loadNextBlocks(block, state);
@@ -427,6 +449,29 @@ const tryToConnectParent = function(parentConnection, child, state) {
   }
 };
 
+/**
+ * Applies icon state to the icons on the block, based on the given state
+ * object.
+ * @param {!Block} block The block to set the icon state of.
+ * @param {!State} state The state object to reference.
+ */
+const loadIcons = function(block, state) {
+  if (!state['icons']) {
+    return;
+  }
+  // TODO(#2105): Remove this logic and put it in the icon.
+  const comment = state['icons']['comment'];
+  if (comment) {
+    block.setCommentText(comment['text']);
+    block.commentModel.pinned = comment['pinned'];
+    block.commentModel.size = new Size(comment['width'], comment['height']);
+    if (comment['pinned'] && block.getCommentIcon && !block.isInFlyout) {
+      // Give the block a chance to be positioned and rendered before showing.
+      setTimeout(() => block.getCommentIcon().setVisible(true), 1);
+    }
+  }
+};
+
 /**
  * Applies any field information available on the state object to the block.
  * @param {!Block} block The block to set the field state of.
diff --git a/tests/deps.js b/tests/deps.js
index a96fa877c1f..13a8463ada0 100644
--- a/tests/deps.js
+++ b/tests/deps.js
@@ -196,7 +196,7 @@ goog.addDependency('../../core/renderers/zelos/renderer.js', ['Blockly.zelos.Ren
 goog.addDependency('../../core/requires.js', ['Blockly.requires'], ['Blockly', 'Blockly.Comment', 'Blockly.ContextMenuItems', 'Blockly.FieldAngle', 'Blockly.FieldCheckbox', 'Blockly.FieldColour', 'Blockly.FieldDropdown', 'Blockly.FieldImage', 'Blockly.FieldLabelSerializable', 'Blockly.FieldMultilineInput', 'Blockly.FieldNumber', 'Blockly.FieldTextInput', 'Blockly.FieldVariable', 'Blockly.FlyoutButton', 'Blockly.Generator', 'Blockly.HorizontalFlyout', 'Blockly.Mutator', 'Blockly.ShortcutItems', 'Blockly.Themes.Classic', 'Blockly.Toolbox', 'Blockly.Trashcan', 'Blockly.VariablesDynamic', 'Blockly.VerticalFlyout', 'Blockly.Warning', 'Blockly.ZoomControls', 'Blockly.geras.Renderer', 'Blockly.serialization.workspaces', 'Blockly.thrasos.Renderer', 'Blockly.zelos.Renderer']);
 goog.addDependency('../../core/scrollbar.js', ['Blockly.Scrollbar'], ['Blockly.Touch', 'Blockly.browserEvents', 'Blockly.utils', 'Blockly.utils.Coordinate', 'Blockly.utils.Svg', 'Blockly.utils.dom'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/scrollbar_pair.js', ['Blockly.ScrollbarPair'], ['Blockly.Events', 'Blockly.Scrollbar', 'Blockly.utils.Svg', 'Blockly.utils.dom'], {'lang': 'es6', 'module': 'goog'});
-goog.addDependency('../../core/serialization/blocks.js', ['Blockly.serialization.blocks'], ['Blockly.Events', 'Blockly.Xml', 'Blockly.inputTypes', 'Blockly.serialization.exceptions'], {'lang': 'es6', 'module': 'goog'});
+goog.addDependency('../../core/serialization/blocks.js', ['Blockly.serialization.blocks'], ['Blockly.Events', 'Blockly.Xml', 'Blockly.inputTypes', 'Blockly.serialization.exceptions', 'Blockly.utils.Size'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/serialization/exceptions.js', ['Blockly.serialization.exceptions'], [], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/serialization/variables.js', ['Blockly.serialization.variables'], ['Blockly.Events'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/serialization/workspaces.js', ['Blockly.serialization.workspaces'], ['Blockly.Events', 'Blockly.Workspace', 'Blockly.serialization.blocks', 'Blockly.serialization.variables', 'Blockly.utils.dom'], {'lang': 'es6', 'module': 'goog'});
diff --git a/tests/mocha/jso_serialization_test.js b/tests/mocha/jso_serialization_test.js
index 83647f5e7ee..51dfe3c27d3 100644
--- a/tests/mocha/jso_serialization_test.js
+++ b/tests/mocha/jso_serialization_test.js
@@ -274,6 +274,67 @@ suite('JSO Serialization', function() {
       });
     });
 
+    suite('Icons', function() {
+      suite('Comment', function() {
+        test('Basic', function() {
+          const block = this.workspace.newBlock('row_block');
+          block.setCommentText('test');
+          const jso = Blockly.serialization.blocks.save(block);
+          assertProperty(
+              jso,
+              'icons',
+              {
+                'comment': {
+                  'text': 'test',
+                  'pinned': false,
+                  'height': 80,
+                  'width': 160,
+                }
+              },
+          );
+        });
+
+        test('Pinned', function() {
+          const block = this.workspace.newBlock('row_block');
+          block.setCommentText('test');
+          block.commentModel.pinned = true;
+          const jso = Blockly.serialization.blocks.save(block);
+          assertProperty(
+              jso,
+              'icons',
+              {
+                'comment': {
+                  'text': 'test',
+                  'pinned': true,
+                  'height': 80,
+                  'width': 160,
+                }
+              },
+          );
+        });
+
+        test('Size', function() {
+          const block = this.workspace.newBlock('row_block');
+          block.setCommentText('test');
+          block.commentModel.size.height = 40;
+          block.commentModel.size.width = 320;
+          const jso = Blockly.serialization.blocks.save(block);
+          assertProperty(
+              jso,
+              'icons',
+              {
+                'comment': {
+                  'text': 'test',
+                  'pinned': false,
+                  'height': 40,
+                  'width': 320,
+                }
+              },
+          );
+        });
+      });
+    });
+
     suite('Fields', function() {
       class StringStateField extends Blockly.Field {
         constructor(value, validator = undefined, config = undefined) {
diff --git a/tests/mocha/serializer_test.js b/tests/mocha/serializer_test.js
index 466c16859c7..4fd20f901f3 100644
--- a/tests/mocha/serializer_test.js
+++ b/tests/mocha/serializer_test.js
@@ -1834,5 +1834,4 @@ var runSerializerTestSuite = (serializer, deserializer, testSuite) => {
 };
 
 runSerializerTestSuite(null, null, Serializer);
-Serializer.Icons.skip = true;
 runSerializerTestSuite(state => state, state => state, Serializer);