diff --git a/MantidPlot/CMakeLists.txt b/MantidPlot/CMakeLists.txt
index cc947a555925ddfc72204a6c4ebde192c2d53e23..b0b1385fb03413ee25e1b0552b447e539bd61d82 100644
--- a/MantidPlot/CMakeLists.txt
+++ b/MantidPlot/CMakeLists.txt
@@ -896,7 +896,7 @@ set ( MANTIDPLOT_TEST_PY_FILES
 )
 
 if ( MAKE_VATES )
- list  ( MANTIDPLOT_TEST_PY_FILES MantidPlotPVPythonTest.py )
+ list  ( APPEND MANTIDPLOT_TEST_PY_FILES MantidPlotPVPythonTest.py )
 endif ()
 
 if ( 0 )