diff --git a/VERSION b/VERSION
index f7ee0669..47da986f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-9.0.0
+9.1.0
diff --git a/gradle.properties b/gradle.properties
index 89483d25..6a11f910 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,2 +1,2 @@
 LOGSTASH_PATH=../../logstash
-ELASTICSEARCH_TREEISH=main
+ELASTICSEARCH_TREEISH=9.1