diff --git a/test/test_ac_dc_lopf.py b/test/test_ac_dc_lopf.py
index bfac499f3..21fc9013b 100644
--- a/test/test_ac_dc_lopf.py
+++ b/test/test_ac_dc_lopf.py
@@ -22,14 +22,13 @@
 
 def test_lopf():
 
+    csv_folder_name = os.path.join(os.path.dirname(__file__), "../examples/ac-dc-meshed/ac-dc-data")
 
-    csv_folder_name = "../examples/ac-dc-meshed/ac-dc-data"
-
-    network = pypsa.Network(csv_folder_name=csv_folder_name)
+    network = pypsa.Network(csv_folder_name)
 
     results_folder_name = os.path.join(csv_folder_name,"results-lopf")
 
-    network_r = pypsa.Network(csv_folder_name=results_folder_name)
+    network_r = pypsa.Network(results_folder_name)
 
 
     #test results were generated with GLPK; solution should be unique,
diff --git a/test/test_ac_dc_lpf.py b/test/test_ac_dc_lpf.py
index df7aaa62c..d3774876f 100644
--- a/test/test_ac_dc_lpf.py
+++ b/test/test_ac_dc_lpf.py
@@ -21,15 +21,13 @@
 
 
 def test_lpf():
+    csv_folder_name = os.path.join(os.path.dirname(__file__), "../examples/ac-dc-meshed/ac-dc-data")
 
+    network = pypsa.Network(csv_folder_name)
 
-    csv_folder_name = "../examples/ac-dc-meshed/ac-dc-data"
+    results_folder_name = os.path.join(csv_folder_name, "results-lpf")
 
-    network = pypsa.Network(csv_folder_name=csv_folder_name)
-
-    results_folder_name = os.path.join(csv_folder_name,"results-lpf")
-
-    network_r = pypsa.Network(csv_folder_name=results_folder_name)
+    network_r = pypsa.Network(results_folder_name)
 
     for snapshot in network.snapshots[:2]:
         network.lpf(snapshot)
diff --git a/test/test_opf_storage.py b/test/test_opf_storage.py
index 265bd2266..62a21df35 100644
--- a/test/test_opf_storage.py
+++ b/test/test_opf_storage.py
@@ -22,9 +22,9 @@
 def test_opf():
 
 
-    csv_folder_name = "../examples/opf-storage-hvdc/opf-storage-data"
+    csv_folder_name = os.path.join(os.path.dirname(__file__), "../examples/opf-storage-hvdc/opf-storage-data")
 
-    network = pypsa.Network(csv_folder_name=csv_folder_name)
+    network = pypsa.Network(csv_folder_name)
 
     #test results were generated with GLPK and other solvers may differ
     solver_name = "glpk"
diff --git a/test/test_sclopf_scigrid.py b/test/test_sclopf_scigrid.py
index e68b5fd97..ae700ed1b 100644
--- a/test/test_sclopf_scigrid.py
+++ b/test/test_sclopf_scigrid.py
@@ -1,17 +1,14 @@
 from __future__ import print_function, division
 from __future__ import absolute_import
 
-import pypsa
-
+import os
 import numpy as np
-
+import pypsa
 
 def test_sclopf():
+    csv_folder_name = os.path.join(os.path.dirname(__file__), "../examples/scigrid-de/scigrid-with-load-gen-trafos/")
 
-
-    csv_folder_name = "../examples/scigrid-de/scigrid-with-load-gen-trafos/"
-
-    network = pypsa.Network(csv_folder_name=csv_folder_name)
+    network = pypsa.Network(csv_folder_name)
 
     #test results were generated with GLPK and other solvers may differ
     solver_name = "cbc"