diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f2b14fc..f86abed 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.7, 3.8, 3.9]
     steps:
     - name: Checkout repository and submodules
       uses: actions/checkout@v2
@@ -31,15 +31,15 @@ jobs:
       run: make test
     - name: Lint with flake8 ⚙️
       run: make lint
-      if: matrix.python-version == 3.6
+      if: matrix.python-version == 3.7
     # - name: Check formatting with black ⚙️
-    #   run: black --check --target-version py36 birdy tests
-    #   if: matrix.python-version == 3.6
+    #   run: black --check --target-version py37 birdy tests
+    #   if: matrix.python-version == 3.7
     - name: Build docs 🏗️
       run: make docs
-      if: matrix.python-version == 3.6
+      if: matrix.python-version == 3.7
     # - name: Run smoke tests ⚙️
     #   run: |
     #     export PYWPS_CFG=$PWD/etc/smoke-pywps.cfg
     #     make smoke
-    #   if: matrix.python-version == 3.6
+    #   if: matrix.python-version == 3.7
diff --git a/environment.yml b/environment.yml
index ca9fe53..efeec26 100644
--- a/environment.yml
+++ b/environment.yml
@@ -3,10 +3,10 @@ channels:
 #- defaults
 - conda-forge
 dependencies:
-- python=3.6
 - pip
+- python>=3.7,<3.10
 # pywps
-- pywps=4.4
+- pywps>=4.5.1,<4.6
 - jinja2
 - click
 - psutil
diff --git a/requirements.txt b/requirements.txt
index f3492f6..0f2acb5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-pywps>=4.4
+pywps>=4.5.1
 jinja2
 click
 psutil
diff --git a/setup.py b/setup.py
index c2430b4..33c199f 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@
 here = os.path.abspath(os.path.dirname(__file__))
 README = open(os.path.join(here, 'README.rst')).read()
 CHANGES = open(os.path.join(here, 'CHANGES.rst')).read()
-REQUIRES_PYTHON = ">=3.6.0"
+REQUIRES_PYTHON = ">=3.7.0"
 
 about = {}
 with open(os.path.join(here, 'hummingbird', '__version__.py'), 'r') as f:
@@ -32,9 +32,9 @@
     'Programming Language :: Python',
     'Natural Language :: English',
     'Programming Language :: Python :: 3',
-    'Programming Language :: Python :: 3.5',
-    'Programming Language :: Python :: 3.6',
     'Programming Language :: Python :: 3.7',
+    'Programming Language :: Python :: 3.8',
+    'Programming Language :: Python :: 3.9',
     'Topic :: Scientific/Engineering :: Atmospheric Science',
     'License :: OSI Approved :: Apache Software License',
 ]