diff --git a/src/action/mod.rs b/src/action/mod.rs
new file mode 100644
index 0000000..ee66949
--- /dev/null
+++ b/src/action/mod.rs
@@ -0,0 +1,4 @@
+mod ports_tree;
+
+pub(crate) use ports_tree::update_ports_tree;
+pub(crate) use ports_tree::ACTION_UPDATE_PORTS_TREE;
diff --git a/src/action/ports_tree.rs b/src/action/ports_tree.rs
new file mode 100644
index 0000000..b4c4c74
--- /dev/null
+++ b/src/action/ports_tree.rs
@@ -0,0 +1,25 @@
+use std::process::Command;
+use std::time::Duration;
+use std::time::SystemTime;
+
+use crate::db::DbHandle;
+
+pub(crate) const ACTION_UPDATE_PORTS_TREE: &str = "update_ports_tree";
+const ACTION_UPDATE_PORTS_TREE_INTERVAL: u64 = 86400;
+
+pub(crate) fn update_ports_tree(db_conn: &mut DbHandle) -> Result<(), Box<dyn std::error::Error>> {
+    println!("Updating ports tree.");
+    Command::new("portshaker").arg("-U").status()?;
+    Command::new("portshaker").arg("-M").status()?;
+    let next_run = (SystemTime::now() + Duration::from_secs(ACTION_UPDATE_PORTS_TREE_INTERVAL))
+        .duration_since(SystemTime::UNIX_EPOCH)?
+        .as_secs();
+
+    let tx = db_conn.conn.transaction()?;
+    tx.execute(
+        "UPDATE global_action SET next_run=$1 WHERE name=$2",
+        (next_run, ACTION_UPDATE_PORTS_TREE),
+    )?;
+    tx.commit()?;
+    Ok(())
+}
diff --git a/src/db/init.rs b/src/db/init.rs
index d37366c..a0a3629 100644
--- a/src/db/init.rs
+++ b/src/db/init.rs
@@ -11,7 +11,7 @@ use super::DbLocalAction;
 static DB_INIT_QUERY: &str = include_str!("../../migrations/01_init.sql");
 
 pub(crate) struct DbHandle {
-    conn: Connection,
+    pub(crate) conn: Connection,
 }
 
 impl DbHandle {
diff --git a/src/main.rs b/src/main.rs
index 100f05f..cc4751c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,8 @@
 use std::{thread, time};
 
+use crate::action::update_ports_tree;
+
+mod action;
 mod db;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
@@ -9,6 +12,19 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut db_conn: db::DbHandle = db::DbHandle::new(db_path)?;
 
     loop {
+        for pending_global_action in db_conn.get_pending_global_actions()? {
+            match pending_global_action.name.as_str() {
+                ACTION_UPDATE_PORTS_TREE => {
+                    update_ports_tree(&mut db_conn)?;
+                }
+                _ => {
+                    panic!("Unknown global action: {}", pending_global_action.name);
+                }
+            };
+        }
+
+        let pending_local_actions = db_conn.get_pending_local_actions()?;
+
         let time_until_next_action = db_conn.get_time_until_next_action()?;
         let sleep_duration = std::cmp::min(
             time::Duration::from_secs(60),