diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 844319f..f887bbd 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -10,12 +10,7 @@ jobs:
     strategy:
       matrix:
         python-version:
-          - '3.5'
-          - '3.6'
-          - '3.7'
           - '3.8'
-          - '3.9'
-          - 'pypy3'
 
     steps:
       - name: Checkout code
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1d52cf2..123b773 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -17,12 +17,12 @@ jobs:
         os:
           - 'ubuntu-latest'
         python-version:
-          - '3.5'
           - '3.6'
           - '3.7'
           - '3.8'
           - '3.9'
-          - 'pypy3'
+          - 'pypy-3.6'
+          - 'pypy-3.8'
         java-version:
           - '8'
         plantuml-server-version:
@@ -99,7 +99,7 @@ jobs:
           PRIMARY_JAR_VERSION: ${{ matrix.plantuml-version }}
           ASSISTANT_JAR_VERSION: ${{ matrix.assistant-plantuml-version }}
           TEST_PLANTUML_HOST: http://localhost:18080
-          WORKERS: 4
+          TIMEOUT: '30'
         run: |
           source env.sh
           make unittest WORKERS=${WORKERS}
diff --git a/Makefile b/Makefile
index a6d98dd..8498c35 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,8 @@
 .PHONY: docs pdocs test unittest benchmark
 
-WORKERS  ?=
-RERUN    ?=
+RERUN       ?=
+RERUN_DELAY ?=
+TIMEOUT     ?=
 
 PROJ_DIR := $(shell readlink -f ${CURDIR})
 
@@ -13,12 +14,20 @@ RANGE_DIR      ?= .
 RANGE_TEST_DIR := ${TEST_DIR}/${RANGE_DIR}
 RANGE_SRC_DIR  := ${SRC_DIR}/${RANGE_DIR}
 
-CI_DEFAULT_RERUNS       := 5
-CI_DEFAULT_RERUNS_DELAY := 10
-DEFAULT_RERUNS          := 3
-DEFAULT_RERUNS_DELAY    := 5
-RERUNS                  ?= $(if ${CI},${CI_DEFAULT_RERUNS},${DEFAULT_RERUNS})
-RERUNS_DELAY            ?= $(if ${CI},${CI_DEFAULT_RERUNS_DELAY},${DEFAULT_RERUNS_DELAY})
+CI_DEFAULT_RERUN          := 5
+LOCAL_DEFAULT_RERUN       := 3
+DEFAULT_RERUN             ?= $(if ${CI},${CI_DEFAULT_RERUN},${LOCAL_DEFAULT_RERUN})
+ACTUAL_RERUN              := $(if ${RERUN},${RERUN},${DEFAULT_RERUN})
+
+CI_DEFAULT_RERUN_DELAY    := 10
+LOCAL_DEFAULT_RERUN_DELAY := 5
+DEFAULT_RERUN_DELAY       ?= $(if ${CI},${CI_DEFAULT_RERUN_DELAY},${LOCAL_DEFAULT_RERUN_DELAY})
+ACTUAL_RERUN_DELAY        := $(if ${RERUN_DELAY},${RERUN_DELAY},${DEFAULT_RERUN_DELAY})
+
+CI_DEFAULT_TIMEOUT        := 30
+LOCAL_DEFAULT_TIMEOUT     := 15
+DEFAULT_TIMEOUT           ?= $(if ${CI},${CI_DEFAULT_TIMEOUT},${LOCAL_DEFAULT_TIMEOUT})
+ACTUAL_TIMEOUT            := $(if ${TIMEOUT},${TIMEOUT},${DEFAULT_TIMEOUT})
 
 COV_TYPES ?= xml term-missing
 
@@ -30,14 +39,14 @@ unittest:
 		$(shell for type in ${COV_TYPES}; do echo "--cov-report=$$type"; done) \
 		--cov="${RANGE_SRC_DIR}" \
 		$(if ${MIN_COVERAGE},--cov-fail-under=${MIN_COVERAGE},) \
-		$(if ${WORKERS},-n ${WORKERS},) \
 		--durations=10 \
-		$(if ${CI}${RERUN},--reruns ${RERUNS} --reruns-delay ${RERUNS_DELAY},)
+		$(if ${CI}${ACTUAL_RERUN},--reruns ${ACTUAL_RERUN} --reruns-delay ${ACTUAL_RERUN_DELAY},) \
+		$(if ${ACTUAL_TIMEOUT},--timeout=${ACTUAL_TIMEOUT},)
 
 benchmark:
-	pytest ${RANGE_TEST_DIR} -sv -m benchmark -n 1 --durations=0
+	pytest ${RANGE_TEST_DIR} -sv -m benchmark --durations=0
 
 docs:
 	$(MAKE) -C "${DOC_DIR}" build
 pdocs:
-	$(MAKE) -C "${DOC_DIR}" prod
\ No newline at end of file
+	$(MAKE) -C "${DOC_DIR}" prod
diff --git a/README.md b/README.md
index d49ab9a..7db3880 100644
--- a/README.md
+++ b/README.md
@@ -37,7 +37,7 @@ git clone https://github.com/HansBug/plantumlcli
 cd plantumlcli && pip install .
 ```
 
-Python 3.5+ is required, pypy is also tested to be okay.
+Python 3.6+ is required, pypy is also tested to be okay.
 
 ## Using with cli
 
diff --git a/requirements-doc.txt b/requirements-doc.txt
index b9e7caf..c129058 100644
--- a/requirements-doc.txt
+++ b/requirements-doc.txt
@@ -2,7 +2,7 @@ sphinx~=3.2.0
 sphinx_rtd_theme~=0.4.3
 enum_tools
 sphinx-toolbox
-plantumlcli>=0.0.2
+plantumlcli>=0.0.4
 packaging
 sphinx-multiversion~=0.2.4
 where~=1.0.2
diff --git a/requirements-test.txt b/requirements-test.txt
index 4df6697..580eeb1 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -1,8 +1,7 @@
 flake8~=3.5
-pytest~=5.1
-pytest-cov~=2.10
-pytest-mock~=3.3
-pytest-forked~=1.3
-pytest-xdist~=1.31
-pytest-rerunfailures~=9.0
-more-itertools>=7,<8
\ No newline at end of file
+pytest~=6.2.5
+pytest-cov~=3.0.0
+pytest-mock~=3.6.1
+pytest-rerunfailures~=10.2
+pytest-timeout~=2.0.2
+more-itertools>=7,<8
diff --git a/setup.py b/setup.py
index 69895a1..7a8690f 100644
--- a/setup.py
+++ b/setup.py
@@ -46,7 +46,7 @@ def _load_req(file: str):
     url='https://github.com/HansBug/plantumlcli',
 
     # environment
-    python_requires=">=3.5",
+    python_requires=">=3.6",
     install_requires=requirements,
     tests_require=group_requirements['test'],
     extras_require=group_requirements,
@@ -56,7 +56,6 @@ def _load_req(file: str):
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
diff --git a/test/entrance/test_cli.py b/test/entrance/test_cli.py
index 91343a5..7d0b8f3 100644
--- a/test/entrance/test_cli.py
+++ b/test/entrance/test_cli.py
@@ -253,7 +253,7 @@ def test_url_error(self):
         assert result.exit_code != 0
 
     @mark_select(_helloworld_condition)
-    def test_concurrency_error(self):
+    def test_concurrency(self):
         runner = CliRunner()
         result = runner.invoke(cli, args=['-u', '-n', '4', DEMO_HELLOWORLD_PUML, DEMO_HELLOWORLD_PUML,
                                           DEMO_HELLOWORLD_PUML, DEMO_HELLOWORLD_PUML])