diff --git a/tests/test_model/test_reftek/test_core.py b/tests/test_model/test_reftek/test_core.py
index 8036702536584dccdc314a6886d00876621f3636..c485d1fb04bc005525288fc00c32feb7dd24b402 100644
--- a/tests/test_model/test_reftek/test_core.py
+++ b/tests/test_model/test_reftek/test_core.py
@@ -10,7 +10,8 @@ from sohstationviewer.model.reftek_data.reftek_reader.core import (
     DiscontinuousTrace,
     Reftek130,
 )
-from sohstationviewer.model.reftek_data.reftek_reader.header import NotRT130FileError
+from sohstationviewer.model.reftek_data.reftek_reader.header import \
+    NotRT130FileError
 
 
 class TestDiscontinuousTrace(unittest.TestCase):
diff --git a/tests/test_model/test_reftek/test_packet_readers.py b/tests/test_model/test_reftek/test_packet_readers.py
index 175a61774eebc07d879ecbd1e9d48266728c0c9f..6494b416bc37b5af2d82cbaf50c3b3a750abd23b 100644
--- a/tests/test_model/test_reftek/test_packet_readers.py
+++ b/tests/test_model/test_reftek/test_packet_readers.py
@@ -8,7 +8,8 @@ from sohstationviewer.model.reftek_data.reftek_reader.packet_readers import (
     decode_uncompressed, decode_compressed, read_dt_packet, read_eh_et_packet,
     read_soh_packet,
 )
-from sohstationviewer.model.reftek_data.reftek_reader.packets import SOHExtendedHeader
+from sohstationviewer.model.reftek_data.reftek_reader.packets import \
+    SOHExtendedHeader
 
 unpacker = Unpacker('>')
 
diff --git a/tests/test_model/test_reftek/test_reftek_helper.py b/tests/test_model/test_reftek/test_reftek_helper.py
index 66a9089b3ac9334914f2a30cf73cfc798a305cb6..2ab5ffe1aedff03bcfe44a9055ddf1acbea891c2 100644
--- a/tests/test_model/test_reftek/test_reftek_helper.py
+++ b/tests/test_model/test_reftek/test_reftek_helper.py
@@ -6,7 +6,8 @@ from unittest.mock import patch
 from obspy.io.reftek.packet import PACKET_FINAL_DTYPE
 
 from sohstationviewer.model.mseed_data.record_reader_helper import Unpacker
-from sohstationviewer.model.reftek_data.reftek_reader.header import NotRT130FileError
+from sohstationviewer.model.reftek_data.reftek_reader.header import \
+    NotRT130FileError
 from sohstationviewer.model.reftek_data.reftek_reader.packet_readers import (
     read_eh_et_packet, read_dt_packet, read_soh_packet,
 )
@@ -14,7 +15,8 @@ from sohstationviewer.model.reftek_data.reftek_reader.packets import (
     SOHPacket,
     EHETPacket, DTPacket,
 )
-from sohstationviewer.model.reftek_data.reftek_reader.reftek_reader_helper import (
+from sohstationviewer.model.reftek_data.reftek_reader.reftek_reader_helper \
+    import (
     read_rt130_file, convert_packet_to_obspy_format,
 )
 
@@ -29,7 +31,8 @@ class TestReadRT130File(unittest.TestCase):
         )
 
         eh_et_patcher = patch(
-            'sohstationviewer.model.reftek_data.reftek_reader.reftek_reader_helper.'
+            'sohstationviewer.model.reftek_data.reftek_reader.'
+            'reftek_reader_helper.'
             'read_eh_et_packet',
             wraps=read_eh_et_packet
         )
@@ -37,7 +40,8 @@ class TestReadRT130File(unittest.TestCase):
         self.addCleanup(eh_et_patcher.stop)
 
         dt_patcher = patch(
-            'sohstationviewer.model.reftek_data.reftek_reader.reftek_reader_helper.'
+            'sohstationviewer.model.reftek_data.reftek_reader.'
+            'reftek_reader_helper.'
             'read_dt_packet',
             wraps=read_dt_packet
         )
@@ -45,7 +49,8 @@ class TestReadRT130File(unittest.TestCase):
         self.addCleanup(dt_patcher.stop)
 
         soh_patcher = patch(
-            'sohstationviewer.model.reftek_data.reftek_reader.reftek_reader_helper.'
+            'sohstationviewer.model.reftek_data.reftek_reader.'
+            'reftek_reader_helper.'
             'read_soh_packet',
             wraps=read_soh_packet
         )