diff --git a/CHANGES.md b/CHANGES.md
index c61fc1a2ec5..47f6dee70d9 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -7,6 +7,7 @@ Fixed Issues:
 
 * [#13434](http://dev.ckeditor.com/ticket/13434): Fixed: Dialog state indicator broken in Right–To–Left environments.
 * [#13434](http://dev.ckeditor.com/ticket/13434): [IE8-9] Fixed: One drag&drop operation may affect following ones.
+* [#13129](http://dev.ckeditor.com/ticket/13129) Fixed: Block widget blurred after drop followed by undo.
 
 ## CKEditor 4.5.1
 
diff --git a/plugins/widget/plugin.js b/plugins/widget/plugin.js
index d14a72bbf86..fb6ffd636ac 100644
--- a/plugins/widget/plugin.js
+++ b/plugins/widget/plugin.js
@@ -3234,12 +3234,6 @@
 			// and save this state as the one where we want to be taken back when undoing.
 			this.focus();
 
-			// Reset the fake selection, which will be invalidated by insertElementIntoRange.
-			// This avoids a situation when getSelection() still returns a fake selection made
-			// on widget which in the meantime has been moved to other place. That could cause
-			// an error thrown e.g. by saveSnapshot or stateUpdater.
-			editor.getSelection().reset();
-
 			// Drag range will be set in the drop listener.
 			editor.fire( 'drop', {
 				dropRange: dropRange,
diff --git a/tests/plugins/widget/dnd.js b/tests/plugins/widget/dnd.js
index 994878ca0db..dd108d8aaef 100644
--- a/tests/plugins/widget/dnd.js
+++ b/tests/plugins/widget/dnd.js
@@ -448,6 +448,9 @@
 				editor.focus();
 
 				try {
+					// Testing if widget is selected is meaningful only if it is not selected at the beginning. (#13129)
+					assert.isNull( editor.widgets.focused, 'widget not focused before mousedown' );
+
 					img.fire( 'mousedown' );
 
 					// Create dummy line and pretend it's visible to cheat drop listener
@@ -456,12 +459,18 @@
 
 					editor.document.fire( 'mouseup' );
 
+					assert.areSame( widget, editor.widgets.focused, 'widget focused after mouseup' );
+
 					bender.tools.resumeAfter( editor, 'afterPaste', function() {
 						assert.isTrue( pasteCounter.calledOnce, 'paste called once' );
 						assert.isTrue( dragstartCounter.calledOnce, 'dragstart called once' );
 						assert.isTrue( dragendCounter.calledOnce, 'dragend called once' );
 						assert.isTrue( dropCounter.calledOnce, 'drop called once' );
 						assert.areSame( '<div data-widget="testwidget" id="w1">bar</div><p id="a">foo</p>', editor.getData(), 'Widget moved on drop.' );
+
+						// Check if widget is still selected after undo. (#13129)
+						editor.execCommand( 'undo' );
+						assert.areSame( getWidgetById( editor, 'w1' ), editor.widgets.focused, 'widget focused after undo' );
 					} );
 
 					wait();
@@ -541,4 +550,4 @@
 			} );
 		}
 	} );
-} )();
\ No newline at end of file
+} )();