diff -up GridDataFormats-0.4.0/gridData/tests/test_dx.py.float128 GridDataFormats-0.4.0/gridData/tests/test_dx.py
--- GridDataFormats-0.4.0/gridData/tests/test_dx.py.float128	2018-01-12 21:49:01.000000000 +0100
+++ GridDataFormats-0.4.0/gridData/tests/test_dx.py	2018-01-19 14:53:00.185104357 +0100
@@ -85,5 +85,5 @@ def test_write_dx_byte(nptype="uint8", d
 
 
 @raises(ValueError)
-def test_write_dx_ValueError(nptype="float128", dxtype="unknown"):
+def test_write_dx_ValueError(nptype="longdouble", dxtype="unknown"):
     return _test_write_dx(nptype=nptype, dxtype=dxtype)