diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index cff8854b9..ad3e941a7 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python-version: [3.5, 3.6, 3.7, 3.8]
+        python-version: [3.6, 3.7, 3.8, 3.9]
     steps:
     - name: Checkout
       uses: actions/checkout@v2
diff --git a/Makefile b/Makefile
index c2f1832e2..9d8e3a199 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ include utils/makefile.include
 PYOBJECTS = searx
 DOC       = docs
 PY_SETUP_EXTRAS ?= \[test\]
-PYLINT_SEARX_DISABLE_OPTION := I,C,R,W0105,W0212,W0511,W0603,W0613,W0621,W0702,W0703,W1401
+PYLINT_SEARX_DISABLE_OPTION := I,C,R,W0105,W0212,W0511,W0603,W0613,W0621,W0702,W0703,W1401,E1136
 PYLINT_ADDITIONAL_BUILTINS_FOR_ENGINES := supported_languages,language_aliases
 
 include utils/makefile.python
diff --git a/requirements-dev.txt b/requirements-dev.txt
index ed3c1c035..483532723 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,5 +1,4 @@
-mock==4.0.3; python_version >= "3.6"
-mock==2.0.0; python_version < "3.6"
+mock==4.0.3
 nose2[coverage_plugin]==0.9.2
 cov-core==1.15.0
 pycodestyle==2.6.0
@@ -8,16 +7,12 @@ splinter==0.14.0
 transifex-client==0.14.2
 unittest2==1.1.0
 selenium==3.141.0
-twine==3.3.0; python_version >= "3.6"
-twine==1.15.0; python_version < "3.6"
+twine==3.3.0
 Pallets-Sphinx-Themes==1.2.3
-Sphinx==3.4.1; python_version >= '3.6'
-Sphinx==3.0.1; python_version < '3.6'
+Sphinx==3.4.1
 sphinx-issues==1.2.0
 sphinx-jinja==1.1.1
-sphinx-tabs==1.3.0; python_version >= '3.6'
-sphinx-tabs==1.1.13; python_version < '3.6'
+sphinx-tabs==1.3.0
 sphinxcontrib-programoutput==0.16
-sphinx-autobuild==2020.9.1; python_version >= '3.6'
-sphinx-autobuild==0.7.1; python_version < '3.6'
+sphinx-autobuild==2020.9.1
 linuxdoc==20210110
diff --git a/requirements.txt b/requirements.txt
index e0c48ca94..ecf8e0c62 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,7 +6,6 @@ idna==2.10
 jinja2==2.11.2
 lxml==4.6.2
 pygments==2.1.3
-pyopenssl==20.0.1
 python-dateutil==2.8.1
 pyyaml==5.3.1
 requests[socks]==2.25.1
diff --git a/searx/data/__init__.py b/searx/data/__init__.py
index 55a254b13..29ac5b7a2 100644
--- a/searx/data/__init__.py
+++ b/searx/data/__init__.py
@@ -8,8 +8,7 @@ data_dir = Path(__file__).parent
 
 
 def load(filename):
-    # add str(...) for Python 3.5
-    with open(str(data_dir / filename), encoding='utf-8') as fd:
+    with open(data_dir / filename, encoding='utf-8') as fd:
         return json.load(fd)