diff --git a/cmd/pkgManagers.go b/cmd/pkgManagers.go
index 1039d900..fadedf4c 100644
--- a/cmd/pkgManagers.go
+++ b/cmd/pkgManagers.go
@@ -675,6 +675,11 @@ func updatePkgManager(cmd *cobra.Command, args []string) error {
 		return error
 	}
 
+	if pkgmanager.BuiltIn {
+		cmdr.Error.Println(apx.Trans("pkgmanagers.update.error.builtIn"))
+		os.Exit(126)
+	}
+
 	if autoRemove == "" {
 		if !assumeYes {
 			cmdr.Info.Printfln(apx.Trans("pkgmanagers.update.info.askNewCommand"), "autoRemove", pkgmanager.CmdAutoRemove)
diff --git a/locales/en.yml b/locales/en.yml
index 81264f74..d32f63ac 100644
--- a/locales/en.yml
+++ b/locales/en.yml
@@ -168,6 +168,7 @@ pkgmanagers:
     error:
       noName: "No name specified."
       missingCommand: "Missing command for %s."
+      builtIn: "Built-in package managers cannot be modified."
   rm:
     description: "Remove the specified package manager."
     error:
@@ -268,6 +269,7 @@ stacks:
       noPkgManager: "No package manager specified."
       pkgManagerDoesNotExist: "The specified package manager does not exist. Create
         it with 'apx pkgmanagers new' or contact the system administrator."
+      builtIn: "Built-in stacks cannot be modified."
     info:
       askBase: "Type a new base or confirm the current one (%s):"
       askPkgManager: "Choose a new package manager or confirm the current one (%s):"