diff --git a/src/update.rs b/src/update.rs
index 3455841..1f2faf6 100644
--- a/src/update.rs
+++ b/src/update.rs
@@ -30,7 +30,9 @@ const HERDR_UPDATE_COMMAND: &str = "herdr update";
 const HOMEBREW_UPDATE_COMMAND: &str = "brew update && brew upgrade herdr";
 const MISE_UPDATE_COMMAND: &str = "mise upgrade herdr";
 const NIX_UPDATE_COMMAND: &str = "update through Nix";
+const MACPORTS_UPDATE_COMMAND: &str = "sudo port selfupdate && sudo port upgrade herdr";
 const MISE_INSTALLS_DIR_ENV: &str = "MISE_INSTALLS_DIR";
+const MACPORTS_BUILD: bool = option_env!("HERDR_MACPORTS_BUILD").is_some();
 const FAKE_UPDATE_VERSION_ENV: &str = "HERDR_FAKE_UPDATE_VERSION";
 const FAKE_UPDATE_NOTES_VERSION_ENV: &str = "HERDR_FAKE_UPDATE_NOTES_VERSION";
 const DEFAULT_FAKE_UPDATE_NOTES_VERSION: &str = "0.3.0";
@@ -1732,7 +1734,9 @@ fn print_running_session_update_outcomes(
 // ---------------------------------------------------------------------------
 
 pub(crate) fn update_install_command() -> &'static str {
-    if is_homebrew_managed_install() {
+    if MACPORTS_BUILD {
+        MACPORTS_UPDATE_COMMAND
+    } else if is_homebrew_managed_install() {
         HOMEBREW_UPDATE_COMMAND
     } else if is_mise_managed_install() {
         MISE_UPDATE_COMMAND
@@ -1758,6 +1762,10 @@ pub(crate) fn update_install_instruction(install_command: &str) -> String {
         NIX_UPDATE_COMMAND => {
             "detach, update through Nix, then restart this Herdr session when ready".to_string()
         }
+        MACPORTS_UPDATE_COMMAND => {
+            "detach, update Herdr through MacPorts, then restart this Herdr session when ready"
+                .to_string()
+        }
         command => format!("detach, run `{command}`, then restart this Herdr session when ready"),
     }
 }
@@ -1796,7 +1804,9 @@ pub(crate) fn preview_channel_rejection_for_current_install() -> Option<&'static
 
 pub(crate) fn package_manager_channel_update_guidance_for_current_install() -> Option<&'static str>
 {
-    if is_homebrew_managed_install() {
+    if MACPORTS_BUILD {
+        Some("Use MacPorts to update this Herdr install.")
+    } else if is_homebrew_managed_install() {
         Some("Use `brew update && brew upgrade herdr` to update Homebrew installs.")
     } else if is_mise_managed_install() {
         Some("Use `mise upgrade herdr` to update mise installs.")
@@ -1808,7 +1818,11 @@ pub(crate) fn package_manager_channel_update_guidance_for_current_install() -> O
 }
 
 fn preview_channel_rejection_for_exe_path(path: &Path) -> Option<&'static str> {
-    if is_homebrew_managed_exe_path_following_links(path) {
+    if MACPORTS_BUILD {
+        Some(
+            "preview channel is only available for direct Herdr installs; MacPorts installs update through MacPorts",
+        )
+    } else if is_homebrew_managed_exe_path_following_links(path) {
         Some(
             "preview channel is only available for direct Herdr installs; Homebrew installs update through `brew update && brew upgrade herdr`",
         )
@@ -1825,7 +1839,8 @@ fn preview_channel_rejection_for_exe_path(path: &Path) -> Option<&'static str> {
 
 #[cfg(unix)]
 pub(crate) fn is_package_manager_managed_exe_path(path: &Path) -> bool {
-    is_homebrew_managed_exe_path_following_links(path)
+    MACPORTS_BUILD
+        || is_homebrew_managed_exe_path_following_links(path)
         || is_mise_managed_exe_path_following_links(path)
         || is_nix_store_exe_path_following_links(path)
 }
@@ -1960,6 +1975,12 @@ pub fn self_update(options: SelfUpdateOptions) -> Result<Version, String> {
         );
     }
 
+    if MACPORTS_BUILD {
+        return Err(format!(
+            "self-update is disabled for MacPorts installs; run `{MACPORTS_UPDATE_COMMAND}`"
+        ));
+    }
+
     if is_homebrew_managed_install() {
         if channel == UpdateChannel::Preview {
             return Err(