diff --git a/app/src/processing/app/Editor.java b/app/src/processing/app/Editor.java
index c0ae487f9..8c7ec1db3 100644
--- a/app/src/processing/app/Editor.java
+++ b/app/src/processing/app/Editor.java
@@ -1693,10 +1693,11 @@ public class Editor extends JFrame implements RunnerListener {
       document.addUndoableEditListener(new UndoableEditListener() {
         public void undoableEditHappened(UndoableEditEvent e) {
           if (compoundEdit != null) {
-            compoundEdit.addEdit(e.getEdit());
-
+            compoundEdit.addEdit(new CaretAwareUndoableEdit(e.getEdit(), textarea));
           } else if (undo != null) {
             undo.addEdit(new CaretAwareUndoableEdit(e.getEdit(), textarea));
+          }
+          if (compoundEdit != null || undo != null) {
             sketch.setModified(true);
             undoAction.updateUndoState();
             redoAction.updateRedoState();
diff --git a/app/test/processing/app/BlockCommentGeneratesOneUndoActionTest.java b/app/test/processing/app/BlockCommentGeneratesOneUndoActionTest.java
new file mode 100644
index 000000000..555a03fcc
--- /dev/null
+++ b/app/test/processing/app/BlockCommentGeneratesOneUndoActionTest.java
@@ -0,0 +1,41 @@
+package processing.app;
+
+import org.fest.swing.edt.GuiActionRunner;
+import org.fest.swing.edt.GuiQuery;
+import org.fest.swing.fixture.JMenuItemFixture;
+import org.junit.Test;
+import processing.app.helpers.JEditTextAreaFixture;
+
+import java.awt.*;
+
+import static org.junit.Assert.assertEquals;
+
+public class BlockCommentGeneratesOneUndoActionTest extends AbstractGUITest {
+
+  @Test
+  public void shouldUndoAndRedo() throws Exception {
+    JMenuItemFixture menuEditUndo = window.menuItem("menuEditUndo");
+    menuEditUndo.requireDisabled();
+
+    JEditTextAreaFixture jEditTextArea = window.jEditTextArea("editor");
+    String previousText = jEditTextArea.getText();
+
+    jEditTextArea.selectAll();
+
+    GuiActionRunner.execute(new GuiQuery<Frame>() {
+
+      protected Frame executeInEDT() {
+        window.getEditor().handleCommentUncomment();
+        return window.getEditor();
+      }
+
+    });
+
+    menuEditUndo.requireEnabled();
+    menuEditUndo.click();
+
+    assertEquals(previousText, jEditTextArea.getText());
+
+    menuEditUndo.requireDisabled();
+  }
+}
diff --git a/app/test/processing/app/helpers/ArduinoFrameFixture.java b/app/test/processing/app/helpers/ArduinoFrameFixture.java
index aec49a5a8..a5832a904 100644
--- a/app/test/processing/app/helpers/ArduinoFrameFixture.java
+++ b/app/test/processing/app/helpers/ArduinoFrameFixture.java
@@ -1,30 +1,23 @@
 package processing.app.helpers;
 
-import org.fest.swing.core.Robot;
 import org.fest.swing.fixture.FrameFixture;
+import processing.app.Editor;
 import processing.app.syntax.JEditTextArea;
 
-import java.awt.*;
-
 public class ArduinoFrameFixture extends FrameFixture {
 
-  public ArduinoFrameFixture(Frame target) {
-    super(target);
-  }
+  private final Editor editor;
 
-  public ArduinoFrameFixture(org.fest.swing.core.Robot robot, Frame target) {
-    super(robot, target);
-  }
-
-  public ArduinoFrameFixture(Robot robot, String name) {
-    super(robot, name);
-  }
-
-  public ArduinoFrameFixture(String name) {
-    super(name);
+  public ArduinoFrameFixture(Editor editor) {
+    super(editor);
+    this.editor = editor;
   }
 
   public JEditTextAreaFixture jEditTextArea(String name) {
     return new JEditTextAreaFixture(robot, (JEditTextArea) this.robot.finder().find(new JEditTextAreaComponentMatcher(name)));
   }
+
+  public Editor getEditor() {
+    return editor;
+  }
 }