diff --git a/vaex/test/dataset.py b/vaex/test/dataset.py
index <HASH>..<HASH> 100644
--- a/vaex/test/dataset.py
+++ b/vaex/test/dataset.py
@@ -13,7 +13,7 @@ import vaex.execution
 a = vaex.execution.buffer_size_default # will crash if we decide to rename it
 
 # this will make the test execute more code and may show up bugs
-#vaex.execution.buffer_size_default = 3
+vaex.execution.buffer_size_default = 3
 
 vx.set_log_level_exception()
 #vx.set_log_level_off()
testing with smaller bffer size reveals errors more quickly