diff --git a/.travis.yml b/.travis.yml
index 16f9a5d5..c5f1fc4f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,4 +24,5 @@ script:
   - 'coverage run --source=src/onelogin/saml2 --rcfile=tests/coverage.rc setup.py test'
   - 'coverage report -m --rcfile=tests/coverage.rc'
 # - 'pylint src/onelogin/saml2 --rcfile=tests/pylint.rc'
-  - 'flake8 --toml-config pyproject.toml'
+#  - 'flake8 --toml-config pyproject.toml'
+  - 'flake8 .'
diff --git a/pyproject.toml b/pyproject.toml
index 54ce0363..8280a909 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,46 +40,48 @@ lxml = ">=4.6.5, !=4.7.0"
 xmlsec = ">=1.3.9"
 isodate = ">=0.6.1"
 
-[tool.poetry.group.dev]
-optional = true
-
-[tool.poetry.group.dev.dependencies]
-black = "*"
-isort = {version = "^5.10.1", extras = ["pyproject"]}
-flake8 = ">=3.6.0"
-Flake8-pyproject = "^1.1.0.post0"
-flake8-bugbear = "^22.8.23"
-flake8-logging-format = "^0.7.5"
-ipdb = "^0.13.9"
-
-[tool.poetry.group.test]
-optional = true
-
-[tool.poetry.group.test.dependencies]
-freezegun= ">=0.3.11, <=1.1.0"
-pytest = ">=6.0"
-flake8 = ">=3.6.0"
+#[tool.poetry.group.dev]
+#optional = true
+
+#[tool.poetry.group.dev.dependencies]
+#black = "*"
+#isort = {version = "^5.10.1", extras = ["pyproject"]}
+flake8 = { version = ">=3.6.0, <=5.0.0", optional = true}
+#Flake8-pyproject = "^1.1.0.post0"
+#flake8-bugbear = "^22.8.23"
+#flake8-logging-format = "^0.7.5"
+ipdb = { version = "^0.13.9", optional = true}
+#[tool.poetry.group.test.dependencies]
+freezegun= { version = ">=0.3.11, <=1.1.0", optional = true}
+pytest = { version = ">=4.6.11", optional = true}
+coverage = { version = ">=4.5.2", optional = true}
 #pylint = ">=1.9.4"
 
-[tool.poetry.group.coverage]
-optional = true
+[tool.poetry.extras]
+test = ["flake8", "ipdb", "freezegun", "pytest", "coverage"]
 
-[tool.poetry.group.coverage.dependencies]
-coverage = ">=4.5.2"
-pytest-cov = "*"
+#[tool.poetry.group.test]
+#optional = true
 
-[tool.poetry.group.docs]
-optional = true
+#[tool.poetry.group.coverage]
+#optional = true
 
-[tool.poetry.group.docs.dependencies]
-sphinx = "*"
+#[tool.poetry.group.coverage.dependencies]
+#coverage = ">=4.5.2"
+#pytest-cov = "*"
+
+#[tool.poetry.group.docs]
+#optional = true
+
+#[tool.poetry.group.docs.dependencies]
+#sphinx = "*"
 
 [build-system]
-requires = ["poetry-core"]
+requires = ["poetry>=1.1.15"]
 build-backend = "poetry.core.masonry.api"
 
 [tool.pytest.ini_options]
-minversion = "6.0"
+minversion = "4.6.11"
 addopts = "-ra -vvv"
 testpaths = [
     "tests",
diff --git a/setup.py b/setup.py
index 44323e5a..79dfa8d9 100644
--- a/setup.py
+++ b/setup.py
@@ -43,7 +43,7 @@
             'coverage>=4.5.2',
             'freezegun>=0.3.11, <=1.1.0',
 #            'pylint>=1.9.4',
-            'flake8>=3.6.0',
+            'flake8>=3.6.0, <=5.0.0',
             'pytest>=4.6',
         ),
     },