diff --git a/lib/microwaveprop/workers/iemre_fetch_worker.ex b/lib/microwaveprop/workers/iemre_fetch_worker.ex
index f7251bf1..9412797c 100644
--- a/lib/microwaveprop/workers/iemre_fetch_worker.ex
+++ b/lib/microwaveprop/workers/iemre_fetch_worker.ex
@@ -1,6 +1,9 @@
 defmodule Microwaveprop.Workers.IemreFetchWorker do
   @moduledoc false
-  use Oban.Worker, queue: :iemre, max_attempts: 20
+  use Oban.Worker,
+    queue: :iemre,
+    max_attempts: 20,
+    unique: [period: 300, fields: [:args], states: [:scheduled, :available]]
 
   alias Microwaveprop.Weather
   alias Microwaveprop.Weather.IemClient
diff --git a/lib/microwaveprop/workers/rtma_fetch_worker.ex b/lib/microwaveprop/workers/rtma_fetch_worker.ex
index 7a3201fc..4191b80d 100644
--- a/lib/microwaveprop/workers/rtma_fetch_worker.ex
+++ b/lib/microwaveprop/workers/rtma_fetch_worker.ex
@@ -3,7 +3,10 @@ defmodule Microwaveprop.Workers.RtmaFetchWorker do
   Fetches RTMA surface observations for real-time propagation scoring.
   15-minute resolution provides finer temporal detail than HRRR's hourly cycle.
   """
-  use Oban.Worker, queue: :rtma, max_attempts: 10
+  use Oban.Worker,
+    queue: :rtma,
+    max_attempts: 10,
+    unique: [period: 300, fields: [:args], states: [:scheduled, :available]]
 
   alias Microwaveprop.Repo
   alias Microwaveprop.Weather.RtmaClient