diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 63126844..98764e17 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -71,7 +71,8 @@ jobs:
           comment-title: 'Backend Unit Test Results'
           results-path: 'coverage/*.trx'
           coverage-path: 'coverage/**/coverage.cobertura.xml'
-          coverage-threshold: 30
+          # A few points under the 2026-10-04 baseline (72.2% lines) — raise as coverage grows.
+          coverage-threshold: 68
           coverage-type: cobertura
 
   frontend:
diff --git a/Server.UnitTests/NotificationsControllerTests.cs b/Server.UnitTests/NotificationsControllerTests.cs
index 03467639..a04d7f5d 100644
--- a/Server.UnitTests/NotificationsControllerTests.cs
+++ b/Server.UnitTests/NotificationsControllerTests.cs
@@ -112,6 +112,19 @@ public void GetVapidPublicKey_WhenOnlyPublicKeyIsSet_ReturnsNotFound()
 
     // ── Subscribe / Unsubscribe ───────────────────────────────────────────────
 
+    // #462: only 0 (NFL) and 1 (CFB) are real sports — anything else would be stored and then never
+    // match a push, silently cutting that device off.
+    [Fact]
+    public async Task Subscribe_UndefinedSport_IsRejected_AndNothingIsSaved()
+    {
+        var request = new PushSubscriptionRequestDto { Endpoint = "https://push.example/ep1", P256dh = "p", Auth = "a", Sport = (LeagueType)5 };
+
+        var result = await BuildController("user-1").Subscribe(request);
+
+        Assert.IsType<BadRequestObjectResult>(result);
+        await _subscriptionService.DidNotReceive().SubscribeAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string?>(), Arg.Any<LeagueType?>());
+    }
+
     [Fact]
     public async Task Subscribe_ValidRequest_CallsServiceForTheCaller()
     {
diff --git a/Server/Controllers/NotificationsController.cs b/Server/Controllers/NotificationsController.cs
index a753f657..10e819ac 100644
--- a/Server/Controllers/NotificationsController.cs
+++ b/Server/Controllers/NotificationsController.cs
@@ -48,6 +48,9 @@ public async Task<IActionResult> Subscribe([FromBody] PushSubscriptionRequestDto
     {
         if (string.IsNullOrWhiteSpace(request.Endpoint) || string.IsNullOrWhiteSpace(request.P256dh) || string.IsNullOrWhiteSpace(request.Auth))
             return BadRequest("Endpoint, P256dh, and Auth are required.");
+        // Only real sports (0 = NFL, 1 = CFB) — any other value would never match a push.
+        if (request.Sport is { } sport && !Enum.IsDefined(sport))
+            return BadRequest("Sport must be 0 (NFL) or 1 (CFB).");
 
         await subscriptionService.SubscribeAsync(CurrentUserId, request.Endpoint, request.P256dh, request.Auth, request.UserAgent, request.Sport);
         return NoContent();