diff --git a/.dialyzer_ignore.exs b/.dialyzer_ignore.exs
index 2b7ca26..04b4a32 100644
--- a/.dialyzer_ignore.exs
+++ b/.dialyzer_ignore.exs
@@ -37,6 +37,7 @@
   # in the dialyzer PLT; also the aprs library's return type is inferred incorrectly from
   # the compiled beam without full type specs
   {"lib/mix/tasks/aprs.parse_file.ex"},
+  {"lib/mix/tasks/aprsme.user_role.ex"},
 
   # Mix.Task.Compiler PLT limitations: same root cause — Mix.* functions and the
   # Mix.Task.Compiler.Diagnostic struct aren't in the dialyzer PLT.
diff --git a/lib/aprsme/deployment_notifier.ex b/lib/aprsme/deployment_notifier.ex
index 8af4daf..fa215c2 100644
--- a/lib/aprsme/deployment_notifier.ex
+++ b/lib/aprsme/deployment_notifier.ex
@@ -14,9 +14,9 @@ defmodule Aprsme.DeploymentNotifier do
 
   @impl true
   def init(_opts) do
-    if System.get_env("DEPLOYED_AT"),
-      do: :ok = Process.send_after(self(), :notify_deployment, 10_000),
-      else: :ok
+    _ =
+      if System.get_env("DEPLOYED_AT"),
+        do: Process.send_after(self(), :notify_deployment, 10_000)
 
     {:ok, %{}}
   end
diff --git a/lib/aprsme_web/live/map_live/subscriptions.ex b/lib/aprsme_web/live/map_live/subscriptions.ex
index e64ee08..9c0aa16 100644
--- a/lib/aprsme_web/live/map_live/subscriptions.ex
+++ b/lib/aprsme_web/live/map_live/subscriptions.ex
@@ -25,7 +25,7 @@ defmodule AprsmeWeb.MapLive.Subscriptions do
   def teardown(socket) do
     _teardown_connection_monitor(socket)
     _teardown_spatial(socket)
-    _teardown_all_timers(socket)
+    _ = _teardown_all_timers(socket)
     _teardown_batch_tasks(socket)
     :ok
   end
@@ -100,9 +100,9 @@ defmodule AprsmeWeb.MapLive.Subscriptions do
   end
 
   defp _teardown_all_timers(socket) do
-    cancel_if_exists(socket.assigns[:buffer_timer])
-    cancel_if_exists(socket.assigns[:bounds_update_timer])
-    cancel_if_exists(socket.assigns[:hover_end_timer])
+    _ = cancel_if_exists(socket.assigns[:buffer_timer])
+    _ = cancel_if_exists(socket.assigns[:bounds_update_timer])
+    _ = cancel_if_exists(socket.assigns[:hover_end_timer])
   end
 
   defp cancel_if_exists(nil), do: :ok
diff --git a/lib/aprsme_web/live/status_live/index.ex b/lib/aprsme_web/live/status_live/index.ex
index af3a5fd..3cae915 100644
--- a/lib/aprsme_web/live/status_live/index.ex
+++ b/lib/aprsme_web/live/status_live/index.ex
@@ -422,7 +422,7 @@ defmodule AprsmeWeb.StatusLive.Index do
       _ ->
         # Fallback to direct query if cache miss
         status = get_aprs_status()
-        Aprsme.Cache.put(:query_cache, "aprs_status", status, ttl: Aprsme.Cache.to_timeout(second: 10))
+        _ = Aprsme.Cache.put(:query_cache, "aprs_status", status, ttl: Aprsme.Cache.to_timeout(second: 10))
         status
     end
   end
diff --git a/lib/mix/tasks/aprsme.user_role.ex b/lib/mix/tasks/aprsme.user_role.ex
index 19ad7ed..2aa64bc 100644
--- a/lib/mix/tasks/aprsme.user_role.ex
+++ b/lib/mix/tasks/aprsme.user_role.ex
@@ -11,21 +11,29 @@ defmodule Mix.Tasks.Aprsme.UserRole do
 
   @impl Mix.Task
   def run([email, role_name]) when role_name in ["user", "admin"] do
-    Mix.Task.run("app.start")
+    _ = Application.ensure_all_started(:aprsme)
 
     case Aprsme.Accounts.get_user_by_email(email) do
       nil ->
-        Mix.raise("No user found with email #{email}")
+        IO.puts(:stderr, "Error: No user found with email #{email}")
+        System.halt(1)
 
       user ->
         role = String.to_existing_atom(role_name)
 
         case Aprsme.Accounts.set_user_role(user, role) do
-          {:ok, _user} -> Mix.shell().info("Set #{email} role to #{role_name}")
-          {:error, changeset} -> Mix.raise("Could not update role: #{inspect(changeset.errors)}")
+          {:ok, _user} ->
+            IO.puts("Set #{email} role to #{role_name}")
+
+          {:error, changeset} ->
+            IO.puts(:stderr, "Error: Could not update role: #{inspect(changeset.errors)}")
+            System.halt(1)
         end
     end
   end
 
-  def run(_args), do: Mix.raise("Usage: mix aprsme.user_role EMAIL user|admin")
+  def run(_args) do
+    IO.puts(:stderr, "Usage: mix aprsme.user_role EMAIL user|admin")
+    System.halt(1)
+  end
 end