diff --git a/set-java-home.nu b/set-java-home.nu
index 55f1ec79..d631f5bc 100644
--- a/set-java-home.nu
+++ b/set-java-home.nu
@@ -1,11 +1,48 @@
-def asdf_update_java_home [] {
-    let $java_path = (asdf which java)
+def --env asdf_update_java_home [] {
+    let result = (do -i { asdf which java } | complete)
 
-    if $java_path {
-        let $full_path = (realpath $java_path | lines | nth 0 | str trim)
+    match $result {
+        { exit_code: 0, stdout: $s } if ($s | str trim | is-not-empty) => {
+            let java_home = (
+                $s
+                | lines | first | str trim
+                | path expand
+                | path dirname | path dirname
+            )
+            $env.JAVA_HOME = $java_home
+            $env.JDK_HOME = $java_home
+        }
+        _ => { hide-env -i JAVA_HOME JDK_HOME }
+    }
+}
+
+def is-asdf-mutating []: string -> bool {
+    let s = ($in | str trim)
+
+    if not ($s like '^\^?asdf(\s|$)') { return false }
+    if ($s like '^\^?asdf\s+(which|where)(\s|$)') { return false }
+    
+    true
+}
 
-        let $java_home = ($full_path | path dirname | path dirname)
-        $env.JAVA_HOME = $java_home
-        $env.JDK_HOME = $java_home
+def --env pre_execution_hook [] {
+    let line = (commandline)
+
+    if ($line | is-asdf-mutating) {
+        $env._ASDF_REFRESH_NEEDED = true
+    } else {
+        hide-env -i _ASDF_REFRESH_NEEDED
     }
 }
+
+def --env pre_prompt_hook [] {
+    if ($env._ASDF_REFRESH_NEEDED? | default false) {
+        asdf_update_java_home
+        hide-env -i _ASDF_REFRESH_NEEDED
+    }
+}
+
+$env.config.hooks = $env.config.hooks
+    | upsert pre_execution { $in | default [] | append { pre_execution_hook } }
+    | upsert pre_prompt { $in | default [] | append { pre_prompt_hook } }
+    | upsert env_change.PWD { $in | default [] | append { asdf_update_java_home } }