diff --git a/tox.ini b/tox.ini
index 9ba99c2af..a05163f2f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -70,7 +70,7 @@ commands_pre =
     python -m pip install \
         --upgrade \
         --upgrade-strategy eager \
-        '{toxinidir}[brille]'
+        '{toxinidir}[brille,matplotlib]'
 commands = {[testenv]test_command} --cov -m "brille and not multiple_extras"
 
 # Run remaining tests that require multiple extras