diff --git a/Qt/Widgets/CMakeLists.txt b/Qt/Widgets/CMakeLists.txt
index 62ee981..c6df205 100644
--- a/Qt/Widgets/CMakeLists.txt
+++ b/Qt/Widgets/CMakeLists.txt
@@ -236,8 +236,7 @@ vtk_module_library(${vtk-module} ${QT_WIDGETS_ALL_SRCS})
 target_link_libraries(${vtk-module} ${QT_LIBRARIES})
 
 if (PQWIDGETS_DISABLE_QTWEBKIT)
-  set_target_properties(${vtk-module}
-    PROPERTIES DEFINE_SYMBOL PQWIDGETS_DISABLE_QTWEBKIT)
+  add_definitions(-DPQWIDGETS_DISABLE_QTWEBKIT)
 endif()
 
 #IF (NOT PV_INSTALL_NO_DEVELOPMENT)