diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 690037d1..eb95a949 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -62,7 +62,7 @@ jobs:
         displayName: install tox & codecov
       - script: tox -e $(tox.env)
         env:
-          TOX_AP_TEST_EXTRAS=azure-pipelines
+          TOX_AP_TEST_EXTRAS: azure-pipelines
         displayName: run tox
       - script: |
           coverage combine