diff --git a/omnioperator/omniop-spark-extension/README.md b/omnioperator/omniop-spark-extension/README.md
index 047f57aa4e3be33d5d4a5fe81ea0f6e4fdf7eb7d..0565b30a8c936a11cb5dc617985b9a21d1f727f8 100644
--- a/omnioperator/omniop-spark-extension/README.md
+++ b/omnioperator/omniop-spark-extension/README.md
@@ -1 +1,2 @@
-# omniop-spark-extension
\ No newline at end of file
+# omniop-spark-extension
+# spark_version=3.1.1
\ No newline at end of file