diff --git a/setup.py b/setup.py
index dffbee26..5f1cb5d0 100644
--- a/setup.py
+++ b/setup.py
@@ -28,7 +28,6 @@ from setuptools import setup, find_packages  # nopep8
 from subprocess import STDOUT, check_output, CalledProcessError  # nopep8
 from collections.abc import Mapping  # nopep8
 import re  # nopep8
-import os  # nopep8
 
 
 missing_program = '''
diff --git a/src/ocrmypdf/_pipeline.py b/src/ocrmypdf/_pipeline.py
index e114d6b6..80cd9093 100644
--- a/src/ocrmypdf/_pipeline.py
+++ b/src/ocrmypdf/_pipeline.py
@@ -33,7 +33,7 @@ from .hocrtransform import HocrTransform
 from .pdfinfo import PdfInfo, Colorspace
 from .pdfa import generate_pdfa_ps, encode_pdf_date
 from .helpers import re_symlink, is_iterable_notstr, page_number, flatten_groups
-from .exec import ghostscript, tesseract, qpdf
+from .exec import ghostscript, tesseract
 from .exceptions import UnsupportedImageFormatError, \
     DpiError, PriorOcrFoundError, InputFileError, EncryptedPdfError
 from . import leptonica
diff --git a/src/ocrmypdf/exec/jbig2enc.py b/src/ocrmypdf/exec/jbig2enc.py
index af4c874c..55d17ac9 100644
--- a/src/ocrmypdf/exec/jbig2enc.py
+++ b/src/ocrmypdf/exec/jbig2enc.py
@@ -15,14 +15,11 @@
 # 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 CalledProcessError, run, PIPE
+from subprocess import run, PIPE
 from functools import lru_cache
-import sys
-import os
-import shutil
 
 from . import get_version
-from ..exceptions import ExitCode, MissingDependencyError
+from ..exceptions import MissingDependencyError
 
 
 @lru_cache(maxsize=1)
diff --git a/src/ocrmypdf/exec/pngquant.py b/src/ocrmypdf/exec/pngquant.py
index 9cedee93..0440ce30 100644
--- a/src/ocrmypdf/exec/pngquant.py
+++ b/src/ocrmypdf/exec/pngquant.py
@@ -15,15 +15,11 @@
 # 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 CalledProcessError, run
-from tempfile import TemporaryFile
+from subprocess import run
 from functools import lru_cache
-import sys
-import os
-import shutil
 
 from . import get_version
-from ..exceptions import ExitCode, MissingDependencyError
+from ..exceptions import MissingDependencyError
 
 
 @lru_cache(maxsize=1)
diff --git a/src/ocrmypdf/exec/qpdf.py b/src/ocrmypdf/exec/qpdf.py
index 33bef631..d0c8b9c5 100644
--- a/src/ocrmypdf/exec/qpdf.py
+++ b/src/ocrmypdf/exec/qpdf.py
@@ -18,8 +18,6 @@
 from subprocess import CalledProcessError, STDOUT, PIPE, run
 from functools import lru_cache
 
-from ..exceptions import InputFileError, SubprocessOutputError, \
-    EncryptedPdfError
 from . import  get_version
 
 
diff --git a/src/ocrmypdf/optimize.py b/src/ocrmypdf/optimize.py
index f48bf843..323a8656 100644
--- a/src/ocrmypdf/optimize.py
+++ b/src/ocrmypdf/optimize.py
@@ -17,7 +17,7 @@
 
 from pathlib import Path
 import concurrent.futures
-from collections import defaultdict, namedtuple
+from collections import defaultdict
 import logging
 import sys
 
@@ -137,10 +137,9 @@ def extract_image_generic(*, pike, root, log, image, xref, options):
         # generating a PNG from compressed data
         pim.as_pil_image().save(png_name(root, xref))
         return xref, '.png'
-    else:
-        return None
 
-    return True
+    return None
+
 
 
 def extract_images(pike, root, log, options, extract_fn):
diff --git a/src/ocrmypdf/pdfa.py b/src/ocrmypdf/pdfa.py
index 8e3df597..a84b83e6 100644
--- a/src/ocrmypdf/pdfa.py
+++ b/src/ocrmypdf/pdfa.py
@@ -34,7 +34,6 @@ Ghostscript's handling of pdfmark.
 from binascii import hexlify
 from datetime import datetime
 from pathlib import Path
-from shutil import copyfile
 from string import Template
 import pkg_resources
 import os
@@ -42,7 +41,6 @@ import os
 from libxmp.utils import file_to_dict
 from libxmp import consts
 
-from ocrmypdf.helpers import fspath
 
 ICC_PROFILE_RELPATH = 'data/sRGB.icc'