diff --git a/tox.ini b/tox.ini
index 80345cc..f45e454 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,6 +6,7 @@ tox_pip_extensions_ext_pip_custom_platform = true
 [testenv]
 deps =
     -rrequirements-dev.txt
+    yarl!=1.6.0  # that version has a bug where it quotes query parameters, see https://github.com/aio-libs/aiohttp/issues/4972
 setenv =
     PYTHONASYNCIODEBUG=1
 commands =