diff --git a/src/lib/utils/displayLimits.ts b/src/lib/utils/displayLimits.ts
index 77c6161..029ec25 100644
--- a/src/lib/utils/displayLimits.ts
+++ b/src/lib/utils/displayLimits.ts
@@ -1,6 +1,7 @@
 import type { NDKEvent } from '@nostr-dev-kit/ndk';
 import type { VisualizationConfig } from '$lib/stores/visualizationConfig';
 import { isEventId, isCoordinate, parseCoordinate } from './nostr_identifiers';
+import type { NostrEventId } from './nostr_identifiers';
 
 /**
  * Filters events based on visualization configuration
@@ -58,7 +59,7 @@ export function filterByDisplayLimits(events: NDKEvent[], config: VisualizationC
  */
 export function detectMissingEvents(
   events: NDKEvent[], 
-  existingIds: Set<string>,
+  existingIds: Set<NostrEventId>,
   existingCoordinates?: Map<string, NDKEvent>
 ): Set<string> {
   const missing = new Set<string>();
diff --git a/src/lib/utils/nostr_identifiers.ts b/src/lib/utils/nostr_identifiers.ts
index 8e789d7..246fc9b 100644
--- a/src/lib/utils/nostr_identifiers.ts
+++ b/src/lib/utils/nostr_identifiers.ts
@@ -1,9 +1,9 @@
 import { VALIDATION } from './search_constants';
+import type { NostrEventId } from './nostr_identifiers';
 
 /**
  * Nostr identifier types
  */
-export type NostrEventId = string; // 64-character hex string
 export type NostrCoordinate = string; // kind:pubkey:d-tag format
 export type NostrIdentifier = NostrEventId | NostrCoordinate;