diff --git a/src/plugins/platforms/direct2d/CMakeLists.txt b/src/plugins/platforms/direct2d/CMakeLists.txt
index 4cbc7ac986..3d41023bfd 100644
--- a/src/plugins/platforms/direct2d/CMakeLists.txt
+++ b/src/plugins/platforms/direct2d/CMakeLists.txt
@@ -47,7 +47,6 @@ qt_internal_add_plugin(QWindowsDirect2DIntegrationPlugin
         qwindowsdirect2dwindow.cpp qwindowsdirect2dwindow.h
     NO_UNITY_BUILD_SOURCES
         ../windows/qwindowspointerhandler.cpp
-        ../windows/qwindowsmousehandler.cpp
     DEFINES
         QT_NO_CAST_FROM_ASCII
         QT_NO_FOREACH
diff --git a/src/plugins/platforms/windows/CMakeLists.txt b/src/plugins/platforms/windows/CMakeLists.txt
index 4425e78b30..abbcebfcfc 100644
--- a/src/plugins/platforms/windows/CMakeLists.txt
+++ b/src/plugins/platforms/windows/CMakeLists.txt
@@ -38,6 +38,8 @@ qt_internal_add_plugin(QWindowsIntegrationPlugin
         qwindowstheme.cpp qwindowstheme.h
         qwindowsthreadpoolrunner.h
         qwindowswindow.cpp qwindowswindow.h
+    NO_UNITY_BUILD_SOURCES
+        qwindowspointerhandler.cpp
     DEFINES
         QT_NO_CAST_FROM_ASCII
         QT_NO_FOREACH
@@ -66,10 +68,6 @@ qt_internal_add_plugin(QWindowsIntegrationPlugin
         runtimeobject
 )
 
-# Duplicated symbols
-set_source_files_properties(qwindowspointerhandler.cpp qwindowsmousehandler.cpp
-                            PROPERTIES SKIP_UNITY_BUILD_INCLUSION ON)
-
 # Resources:
 set_source_files_properties("openglblacklists/default.json"
     PROPERTIES QT_RESOURCE_ALIAS "default.json"