diff --git a/demo/comparison-oskar/CMakeLists.txt b/demo/comparison-oskar/CMakeLists.txt
index 68e1dd6ac0f562962bd366584f244483fe24a7aa..ae5673a90458e1a32427c921f36bf587327da3a2 100644
--- a/demo/comparison-oskar/CMakeLists.txt
+++ b/demo/comparison-oskar/CMakeLists.txt
@@ -22,7 +22,9 @@ file(COPY "${CMAKE_CURRENT_SOURCE_DIR}/telescope.tm/station000/layout.txt"
 #------------------------------------------------------------------------------
 # comparison-oskar knits together the cpp code and the python scripts     
 add_custom_target(comparison-oskar
-     COMMAND ${CMAKE_COMMAND} -E env EXTRA_PATH="${CMAKE_CURRENT_BINARY_DIR}:${CMAKE_SOURCE_DIR}/scripts/coeff_scripts"
+     COMMAND ${CMAKE_COMMAND} -E env
+         EXTRA_PATH="${CMAKE_CURRENT_BINARY_DIR}:${CMAKE_SOURCE_DIR}/scripts/coeff_scripts"
+         TOLERANCE=1e-12
      "${CMAKE_CURRENT_SOURCE_DIR}/generate_basefunction_plots.sh"
      DEPENDS comparison-oskar-generate-beampattern
 )