diff --git a/nixpacks.toml b/nixpacks.toml
index 40b2065..aff0c73 100644
--- a/nixpacks.toml
+++ b/nixpacks.toml
@@ -1,4 +1,4 @@
 # nixpacks.toml
 
-[phases.setup]
-providers = ["java@21"]
+[variables]
+NIXPACKS_JDK_VERSION = "21"