diff --git a/main.tf b/main.tf
index 7e9c635..6c824a4 100644
--- a/main.tf
+++ b/main.tf
@@ -21,7 +21,7 @@ module "final_snapshot_label" {
 }
 
 locals {
-  computed_major_engine_version = join(".", slice(split(".", var.engine_version), 0, 2))
+  computed_major_engine_version = var.engine == "postgres" ? join(".", slice(split(".", var.engine_version), 0, 1)) : join(".", slice(split(".", var.engine_version), 0, 2))
   major_engine_version          = var.major_engine_version == "" ? local.computed_major_engine_version : var.major_engine_version
 }