diff --git a/requirements_dev.txt b/requirements_dev.txt
index b675b56..c015ef4 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -3,7 +3,7 @@ bump2version==1.0.0
 wheel==0.33.6
 watchdog==0.10.2
 flake8==3.7.9
-tox==3.14.5
+tox==4.0.6
 coverage==5.0.3
 Sphinx==2.4.3
 twine==3.1.1
diff --git a/requirements_test.txt b/requirements_test.txt
index e36b00c..426266b 100644
--- a/requirements_test.txt
+++ b/requirements_test.txt
@@ -3,7 +3,7 @@ pytest-runner==5.2
 pytest-cov==2.8.1
 codecov==2.0.22
 flake8==3.7.9
-tox==3.14.1
+tox==4.0.6
 tox-conda==0.8.0
 coverage==4.5.4
 moto==1.3.14