diff --git a/backend/src/repositories/BlocksRepository.ts b/backend/src/repositories/BlocksRepository.ts
index 80df1ac92..f2d0a283e 100644
--- a/backend/src/repositories/BlocksRepository.ts
+++ b/backend/src/repositories/BlocksRepository.ts
@@ -748,6 +748,7 @@ class BlocksRepository {
         SELECT height
         FROM compact_cpfp_clusters
         WHERE height <= ? AND height >= ?
+        GROUP BY height
         ORDER BY height DESC;
       `, [currentBlockHeight, minHeight]);