diff --git a/tests/test_main.py b/tests/test_main.py
index 1d1e21ec..9d95a189 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -21,6 +21,7 @@ import os
 import shutil
 import resource
 import pytest
+import sys
 from ocrmypdf.pdfinfo import PdfInfo, Colorspace, Encoding
 import PyPDF2 as pypdf
 from ocrmypdf.exceptions import ExitCode
@@ -552,7 +553,7 @@ def test_algo4(resources, no_outpdf):
 
 
 @pytest.mark.parametrize('renderer', [
-    'hocr'])  # tesseract cannot pass this test - resamples to square image
+    'hocr', 'sandwich'])  # tesseract cannot pass this test - resamples to square image
 def test_non_square_resolution(renderer, spoof_tesseract_cache,
                                resources, outpdf):
     # Confirm input image is non-square resolution
@@ -656,6 +657,8 @@ def test_stdout(spoof_tesseract_noop, ocrmypdf_exec, resources, outpdf):
     assert qpdf.check(output_file, log=None)
 
 
+@pytest.mark.skipif(sys.version_info[0:3] >= (3, 6, 4),
+                    reason="issue fixed in Python 3.6.4")
 def test_closed_streams(spoof_tesseract_noop, ocrmypdf_exec, resources, outpdf):
     input_file = str(resources / 'francais.pdf')
     output_file = str(outpdf)
diff --git a/tests/test_unpaper.py b/tests/test_unpaper.py
index 1d3d19ce..3e6357a0 100644
--- a/tests/test_unpaper.py
+++ b/tests/test_unpaper.py
@@ -15,22 +15,9 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from subprocess import Popen, PIPE, check_output, check_call, DEVNULL
 from pathlib import Path
-import os
-import shutil
-import resource
 import pytest
-from ocrmypdf.pdfinfo import PdfInfo, Colorspace, Encoding
-import PyPDF2 as pypdf
 from ocrmypdf.exceptions import ExitCode
-from ocrmypdf import leptonica
-from ocrmypdf.pdfa import file_claims_pdfa
-from ocrmypdf.exec import ghostscript, tesseract, qpdf
-import logging
-from math import isclose
-
-import PIL
 
 # pytest.helpers is dynamic
 # pylint: disable=no-member
@@ -46,7 +33,7 @@ spoof = pytest.helpers.spoof
 def test_no_unpaper(resources, no_outpdf):
     # <disable unpaper here>
     p, out, err = run_ocrmypdf(
-        resources / 'c02-22.pdf', no_outpdf, '--clean', env=env)
+        resources / 'c02-22.pdf', no_outpdf, '--clean', env=os.environ)
     assert p.returncode == ExitCode.missing_dependency