diff --git a/src/modules/activities/composables/useActivityDetail.ts b/src/modules/activities/composables/useActivityDetail.ts
index e29a272..9fc3ce4 100644
--- a/src/modules/activities/composables/useActivityDetail.ts
+++ b/src/modules/activities/composables/useActivityDetail.ts
@@ -32,18 +32,24 @@ export function useActivityDetail(activityId: string) {
       isLoading.value = true
       error.value = null
 
-      // Subscribe and wait for this specific event
+      // Scope both the subscription and the one-shot query to this
+      // activity's d-tag. Without this scope, the query asks every
+      // relay for every kind-31922/31923 event and races a 5s timeout
+      // to find ours — on a cold page refresh that race is often lost
+      // even when the activity is reachable.
+      const detailFilters = { dTags: [activityId] }
+
       unsubscribe = nostrService.subscribeToCalendarEvents(
         (incoming) => {
           store.upsertActivity(incoming)
           if (incoming.id === activityId) {
             isLoading.value = false
           }
-        }
+        },
+        detailFilters
       )
 
-      // Also do a one-shot query
-      const results = await nostrService.queryCalendarEvents()
+      const results = await nostrService.queryCalendarEvents(detailFilters)
       store.upsertActivities(results)
 
       // If we still don't have it after query, stop loading
diff --git a/src/modules/activities/services/ActivitiesNostrService.ts b/src/modules/activities/services/ActivitiesNostrService.ts
index 0b0a00e..4883910 100644
--- a/src/modules/activities/services/ActivitiesNostrService.ts
+++ b/src/modules/activities/services/ActivitiesNostrService.ts
@@ -23,6 +23,8 @@ export interface CalendarEventFilters {
   hashtags?: string[]
   /** Filter by geohash prefix (NIP-52 'g' tag) */
   geohash?: string
+  /** Filter by NIP-52 'd' tag — scopes the query to specific parameterized-replaceable events */
+  dTags?: string[]
 }
 
 /**
@@ -148,6 +150,7 @@ export class ActivitiesNostrService extends BaseService {
     if (filters?.authors?.length) filter.authors = filters.authors
     if (filters?.hashtags?.length) filter['#t'] = filters.hashtags
     if (filters?.geohash) filter['#g'] = [filters.geohash]
+    if (filters?.dTags?.length) filter['#d'] = filters.dTags
 
     return [filter]
   }