diff --git a/Applications/Utils/Tests.cmake b/Applications/Utils/Tests.cmake
index f512fab65635c6c5d693693fd003de575e3f78a4..975093d7b68a8758c0000c3dd1ad9910c3a9fa5a 100644
--- a/Applications/Utils/Tests.cmake
+++ b/Applications/Utils/Tests.cmake
@@ -485,8 +485,7 @@ AddTest(
     EXECUTABLE VerticalSliceFromLayers
     EXECUTABLE_ARGS -i AmmerLayers.txt -o ${Data_BINARY_DIR}/MeshGeoToolsLib/Ammer/AmmerSlice --start-x 3491000 --start-y 5380000 --end-x 3495000 --end-y 5385000 -r 200
     REQUIREMENTS NOT OGS_USE_MPI
-    TESTER diff
-    DIFF_DATA AmmerSlice.vtu
+    DIFF_DATA AmmerSlice.vtu AmmerSlice.vtu 1e-16
 )
 
 AddTest(