diff --git a/src/apps/sudoku/ProgressWindow.cpp b/src/apps/sudoku/ProgressWindow.cpp
index c8d7251190..8bd76ed9bc 100644
--- a/src/apps/sudoku/ProgressWindow.cpp
+++ b/src/apps/sudoku/ProgressWindow.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2007-2011, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2007-2015, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  */
 
@@ -27,7 +27,8 @@ ProgressWindow::ProgressWindow(BWindow* referenceWindow,
 		BMessage* abortMessage)
 	: BWindow(BRect(0, 0, 250, 100), B_TRANSLATE("Progress monitor"),
 		B_MODAL_WINDOW_LOOK, B_FLOATING_APP_WINDOW_FEEL,
-		B_NOT_ZOOMABLE | B_NOT_RESIZABLE | B_ASYNCHRONOUS_CONTROLS),
+		B_NOT_ZOOMABLE | B_NOT_RESIZABLE | B_ASYNCHRONOUS_CONTROLS
+			| B_NO_WORKSPACE_ACTIVATION),
 	fRunner(NULL)
 {
 	BRect rect = Bounds();