diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 2e08d5d..994fef2 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -11,11 +11,11 @@ on:
 
 jobs:
   build_3_6_7_8_django_2_2:
-    name: Build on Python 3.6, 3.7, 3.8 and django 2.2
+    name: Build on Python 3.7, 3.8 and django 2.2
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.7, 3.8]
     steps:
     - name: Checkout
       uses: actions/checkout@v2
diff --git a/README.md b/README.md
index 9cd7c36..77c3f33 100644
--- a/README.md
+++ b/README.md
@@ -201,7 +201,7 @@ kubectl exec -i REPLICA_CONTAINER -- python manage.py cqrs_deleted_diff_replica
 Development
 ===========
 
-1. Python 3.6+
+1. Python 3.7 +
 0. Install dependencies `requirements/dev.txt`
 
 Testing
@@ -209,7 +209,7 @@ Testing
 
 Unit testing
 ------
-1. Python 3.6+
+1. Python 3.7 +
 2. Install dependencies `requirements/test.txt`
 3. `export PYTHONPATH=/your/path/to/django-cqrs/`
 
diff --git a/requirements/dev.txt b/requirements/dev.txt
index efa79b8..5897af1 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -1,6 +1,6 @@
 Django>=2.2.19
 pika>=1.0.0
 kombu>=4.6.*
-ujson>=3.0.0
+ujson>=5.4.0
 django-model-utils>=4.0.0
 python-dateutil>=2.4
diff --git a/setup.py b/setup.py
index 343cd05..aca8701 100644
--- a/setup.py
+++ b/setup.py
@@ -18,7 +18,7 @@ def read_file(name):
     long_description_content_type='text/markdown',
     license='Apache License, Version 2.0',
 
-    python_requires='>=3.6',
+    python_requires='>=3.7',
     zip_safe=True,
     packages=find_packages(),
     include_package_data=True,
@@ -38,7 +38,6 @@ def read_file(name):
         'Intended Audience :: Developers',
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: Unix',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',