diff --git a/CMakeLists.txt b/CMakeLists.txt
index b7101666c..ebac50016 100644
--- a/CMakeLists.txt	
+++ b/CMakeLists.txt
@@ -592,6 +592,9 @@ set(_paraview_add_tests_default_data_directory
 set(_paraview_add_tests_default_test_data_target
   "ParaViewData")
 
+list(REMOVE_DUPLICATES vtk_modules)    # Missed this somewhere
+list(REMOVE_DUPLICATES paraview_modules) # probably not needed
+
 vtk_module_build(
   MODULES             ${paraview_modules}
   KITS                ${paraview_kits}
