diff --git a/OscarCI.toml b/OscarCI.toml
index 74eff5e4..e01589a3 100644
--- a/OscarCI.toml
+++ b/OscarCI.toml
@@ -1,7 +1,7 @@
 title = "metadata for oscar CI run"
 
 [env]
-  os = ["Linux", "RPTU"]
+  os = [ ["Linux", "RPTU"] ]
 # julia-version = [ "~1.6.0-0"]
 # branches = [ "release", "<matching>" ]