diff --git a/dev_requirements.txt b/dev_requirements.txt
--- a/dev_requirements.txt
+++ b/dev_requirements.txt
@@ -4,5 +4,5 @@ pytest-benchmark >= 3.2.2, < 3.3
 pytest-localserver >= 0.5.0, < 0.6
 mock >= 3.0.0, < 3.1
 Sphinx >= 1.8.0, < 1.9
-WebTest >= 2.0.3, < 2.1
+WebTest >= 2.0.6, < 2.1
 isort == 4.3.21