diff --git a/app/modules/dump/wotwizard/hooks/wotwizard.block.insert.ts b/app/modules/dump/wotwizard/hooks/wotwizard.block.insert.ts
index 32aba57d017d5da237e2895c0ee379d879fa9922..100c6c990cc832c04db9fad0c2d40688c245fd38 100644
--- a/app/modules/dump/wotwizard/hooks/wotwizard.block.insert.ts
+++ b/app/modules/dump/wotwizard/hooks/wotwizard.block.insert.ts
@@ -42,7 +42,7 @@ export function requiredBlocksAccumulator(server: Server, wwDAL: WotWizardDAL):
       const numbers = Object.keys(blockNumbers).map(n => parseInt(n))
       const blocksForCertifications: (DBBlock|null)[] = []
       for (let i = 0; i < numbers.length; i += chunkLen) {
-        const chunk = numbers.slice(0, chunkLen)
+        const chunk = numbers.slice(0, chunkLen + 1)
         logger.debug('Chunk %s-%s', i, i + chunkLen)
         ;(await Promise.all(chunk.map(n => server.dal.getBlock(n))))
           .forEach(b => blocksForCertifications.push(b))