diff --git a/app/Http/Controllers/HashtagFollowController.php b/app/Http/Controllers/HashtagFollowController.php
index b5cc49d41..79b6e9f53 100644
--- a/app/Http/Controllers/HashtagFollowController.php
+++ b/app/Http/Controllers/HashtagFollowController.php
@@ -23,13 +23,16 @@ class HashtagFollowController extends Controller
 
         $user = $request->user();
         $profile = $user->profile;
+
+        abort_if(! $profile, 422, 'Profile not available for this account.');
+
         $tag = $request->input('name');
 
         $hashtag = Hashtag::whereName($tag)->firstOrFail();
 
         $hashtagFollow = HashtagFollow::firstOrCreate([
             'user_id' => $user->id,
-            'profile_id' => $user->profile_id ?? $user->profile->id,
+            'profile_id' => $user->profile_id ?? $profile->id,
             'hashtag_id' => $hashtag->id,
         ]);
 
diff --git a/tests/Feature/HashtagFollowProfileGuardTest.php b/tests/Feature/HashtagFollowProfileGuardTest.php
new file mode 100644
index 000000000..6f4f54814
--- /dev/null
+++ b/tests/Feature/HashtagFollowProfileGuardTest.php
@@ -0,0 +1,49 @@
+<?php
+
+use App\Models\Hashtag;
+use App\Models\User;
+use Illuminate\Foundation\Testing\LazilyRefreshDatabase;
+
+uses(LazilyRefreshDatabase::class);
+
+/*
+|--------------------------------------------------------------------------
+| HashtagFollowController profile guard
+|--------------------------------------------------------------------------
+|
+| store() dereferences $user->profile->id when calling HashtagService. A user
+| whose profile has been soft-deleted (e.g. via admin account deletion) keeps a
+| live session but has a null profile relationship, so the endpoint must fail
+| deterministically (422) instead of throwing a 500.
+|
+*/
+
+it('follows a hashtag for a normal authenticated user', function () {
+    $user = User::factory()->create();
+    $user->refresh();
+
+    Hashtag::create(['name' => 'landscape', 'slug' => 'landscape']);
+
+    $this->actingAs($user)
+        ->postJson('/api/local/discover/tag/subscribe', ['name' => 'landscape'])
+        ->assertOk()
+        ->assertJson(['state' => 'created']);
+});
+
+it('returns 422 instead of 500 when the profile is soft-deleted', function () {
+    $user = User::factory()->create();
+    $user->refresh();
+
+    Hashtag::create(['name' => 'landscape', 'slug' => 'landscape']);
+
+    // Soft-delete the profile, as the admin account-deletion pipeline does,
+    // while leaving the still-authenticated session intact. Unset the cached
+    // relation so the controller re-queries and sees null, matching what a
+    // fresh request resolves after the pipeline runs in another request.
+    App\Models\Profile::whereUserId($user->id)->delete();
+    $user->unsetRelation('profile');
+
+    $this->actingAs($user)
+        ->postJson('/api/local/discover/tag/subscribe', ['name' => 'landscape'])
+        ->assertStatus(422);
+});