diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b38618820ff57512c77f9ada84ebf454572658c8..2e7f1865220b46ad055f2e13e46a88023d888f66 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -41,6 +41,7 @@ test_styles:
     - source /root/miniconda3/bin/activate
     - export GDAL_DATA=/root/miniconda3/share/gdal
     - export PYTHONPATH=$PYTHONPATH:/root  # /root <- directory needed later
+    - pip install "pycodestyle>=2.0.0,!=2.4.0"  # TODO remove as soon as docker runner is recreated
     - make lint
   artifacts:
     paths:
diff --git a/geoarray/baseclasses.py b/geoarray/baseclasses.py
index cde614378584f1993d77dc304af2a6b84a995e33..01030fd4faca32ba69b14ce95eb9f29f4b0112e0 100644
--- a/geoarray/baseclasses.py
+++ b/geoarray/baseclasses.py
@@ -159,21 +159,26 @@ class GeoArray(object):
         # type: (list) -> None
 
         if list_bandnames:
-            assert isinstance(list_bandnames, list), "A list must be given when setting the 'bandnames' attribute. " \
-                                                     "Received %s." % type(list_bandnames)
-            assert len(list_bandnames) == self.bands, \
-                'Number of given bandnames does not match number of bands in array.'
-            assert len(list(set([type(b) for b in list_bandnames]))) == 1 and type(list_bandnames[0] == 'str'), \
-                "'bandnames must be a set of strings. Got other datetypes in there.'"
+            if not isinstance(list_bandnames, list):
+                raise TypeError("A list must be given when setting the 'bandnames' attribute. "
+                                "Received %s." % type(list_bandnames))
+            if len(list_bandnames) != self.bands:
+                raise ValueError('Number of given bandnames does not match number of bands in array.')
+            if len(list(set([type(b) for b in list_bandnames]))) != 1 or not isinstance(list_bandnames[0], str):
+                raise ValueError("'bandnames must be a set of strings. Got other datatypes in there.'")
+
             bN_dict = OrderedDict((band, i) for i, band in enumerate(list_bandnames))
-            assert len(bN_dict) == self.bands, \
-                'Bands must not have the same name. Received band list: %s' % list_bandnames
+
+            if len(bN_dict) != self.bands:
+                raise ValueError('Bands must different names. Received band list: %s' % list_bandnames)
 
             self._bandnames = bN_dict
 
-            # update bandnames in metadata
-            if self._metadata is not None:
+            try:
                 self.metadata.band_meta['band_names'] = list_bandnames
+            except AttributeError:
+                # in case self._metadata is None
+                pass
         else:
             del self.bandnames
 
@@ -893,6 +898,12 @@ class GeoArray(object):
 
             # write dataset
             ds_out = driver.CreateCopy(out_path, ds_inmem, options=creationOptions if creationOptions else [])
+
+            # # rows, columns, bands => bands, rows, columns
+            # out_arr = self.arr if self.ndim == 2 else np.swapaxes(np.swapaxes(self.arr, 0, 2), 1, 2)
+            # gdalnumeric.SaveArray(out_arr, out_path, format=fmt, prototype=ds_inmem)  # expects bands,rows,columns
+            # ds_out = gdal.Open(out_path)
+
             del ds_inmem
 
             ################
@@ -909,7 +920,10 @@ class GeoArray(object):
                 if 'band_names' in envi_metadict:
                     for bidx in range(self.bands):
                         band = ds_out.GetRasterBand(bidx + 1)
-                        band.SetDescription(self.metadata.band_meta['band_names'][bidx].strip())
+                        bandname = self.metadata.band_meta['band_names'][bidx].strip()
+                        band.SetDescription(bandname)
+
+                        assert band.GetDescription() == bandname
                         del band
 
                 if 'description' in envi_metadict:
@@ -939,10 +953,6 @@ class GeoArray(object):
                         del band
 
             ds_out.FlushCache()
-
-            # rows, columns, bands => bands, rows, columns
-            # out_arr = self.arr if self.ndim == 2 else np.swapaxes(np.swapaxes(self.arr, 0, 2), 1, 2)
-            # gdalnumeric.SaveArray(out_arr, out_path, format=fmt, prototype=ds) # expects bands,rows,columns
             del ds_out
 
         else:
diff --git a/tests/CI_docker/context/environment_geoarray.yml b/tests/CI_docker/context/environment_geoarray.yml
index f5c2e0e9f487c1b28a0c9f847472700ea76fde70..2bb3fe1fd09faf25904129da9a38fa80c9200c3c 100644
--- a/tests/CI_docker/context/environment_geoarray.yml
+++ b/tests/CI_docker/context/environment_geoarray.yml
@@ -33,7 +33,7 @@ dependencies:
     - six
     - spectral
     - flake8
-    - pycodestyle
+    - pycodestyle<2.4.0  # fixes ImportError: module 'pycodestyle' has no attribute 'break_around_binary_operator'
     - pylint
     - pydocstyle
     - nose