diff --git a/tests/base.py b/tests/base.py
old mode 100755
new mode 100644
diff --git a/tests/test_convergence.py b/tests/test_convergence.py
old mode 100755
new mode 100644
diff --git a/tests/test_frozen_field.py b/tests/test_frozen_field.py
old mode 100755
new mode 100644
diff --git a/tests/test_interpolation.py b/tests/test_interpolation.py
old mode 100755
new mode 100644
diff --git a/tests/test_io.py b/tests/test_io.py
old mode 100755
new mode 100644
index 0d8b8c055eae1deea8fbaef0644f050d8a900e3c..447cb405406a61573cc7d7b2b5942d012e6f55f6
--- a/tests/test_io.py
+++ b/tests/test_io.py
@@ -1,4 +1,3 @@
-#! /usr/bin/env python2
 #######################################################################
 #                                                                     #
 #  Copyright 2015 Max Planck Institute                                #
@@ -25,7 +24,7 @@
 
 
 
-from test_base import *
+from base import *
 
 class test_io(bfps.code):
     def __init__(
@@ -43,7 +42,12 @@ class test_io(bfps.code):
         return None
 
 if __name__ == '__main__':
-    opt = parser.parse_args()
+    opt = parser.parse_args(
+            ['-n', '32',
+             '--run',
+             '--initialize',
+             '--ncpu', '2'] +
+            sys.argv[1:])
     c = test_io(work_dir = opt.work_dir + '/io')
     c.write_src()
     c.write_par()
diff --git a/tests/test_particles.py b/tests/test_particles.py
old mode 100755
new mode 100644
diff --git a/tests/test_plain.py b/tests/test_plain.py
old mode 100755
new mode 100644
diff --git a/tests/test_scaling.py b/tests/test_scaling.py
old mode 100755
new mode 100644
diff --git a/tests/test_time_step.py b/tests/test_time_step.py
old mode 100755
new mode 100644
diff --git a/tox_io.ini b/tox_io.ini
deleted file mode 100644
index de8c2fc5d0bb5fa7498527ecb4b96b32ca000c69..0000000000000000000000000000000000000000
--- a/tox_io.ini
+++ /dev/null
@@ -1,14 +0,0 @@
-[tox]
-envlist = py27, py34
-[testenv]
-deps = matplotlib
-whitelist_externals =
-    echo
-    cp
-passenv = LD_LIBRARY_PATH
-changedir =
-    {envtmpdir}
-commands =
-    cp -r {toxinidir}/tests {envtmpdir}
-    python tests/test_io.py -n 32 --run --initialize --ncpu 2
-