diff --git a/.github/workflows/deploy-review.yml b/.github/workflows/deploy-review.yml
index 7263ed0ef0..f38bdb4a99 100644
--- a/.github/workflows/deploy-review.yml
+++ b/.github/workflows/deploy-review.yml
@@ -36,6 +36,7 @@ on:
             - garnet
             - gnosis
             - gnosis_chiado
+            - hpp
             - immutable
             - mega_eth
             - multichain
diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index 3149239214..2b89ab52f1 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -334,6 +334,7 @@
               "garnet",
               "gnosis",
               "gnosis_chiado",
+              "hpp",
               "immutable",
               "mega_eth",
               "multichain",
diff --git a/src/slices/block/pages/details/BlockDetails.tsx b/src/slices/block/pages/details/BlockDetails.tsx
index 13e959c999..41a542e21d 100644
--- a/src/slices/block/pages/details/BlockDetails.tsx
+++ b/src/slices/block/pages/details/BlockDetails.tsx
@@ -694,7 +694,7 @@ const BlockDetails = ({ query }: Props) => {
           </>
         ) }
 
-        { rollupFeature.isEnabled && rollupFeature.type === 'arbitrum' && data.arbitrum && data.arbitrum.send_count && (
+        { rollupFeature.isEnabled && rollupFeature.type === 'arbitrum' && data.arbitrum && typeof data.arbitrum.send_count === 'number' && (
           <>
             <DetailedInfo.ItemLabel
               hint={ `The cumulative number of ${ layerLabels.current } to ${ layerLabels.parent } transactions as of this block` }
diff --git a/tools/dev-server/registry.json b/tools/dev-server/registry.json
index 71b3f2ef17..f2d9fdb270 100644
--- a/tools/dev-server/registry.json
+++ b/tools/dev-server/registry.json
@@ -11,6 +11,7 @@
   "garnet": "https://explorer.garnetchain.com",
   "gnosis": "https://gnosis.blockscout.com",
   "gnosis_chiado": "https://gnosis-chiado.blockscout.com",
+  "hpp": "https://hpp.blockscout.com",
   "immutable": "https://explorer.immutable.com",
   "mega_eth": "https://megaeth.blockscout.com",
   "multichain": "https://explorer.blockscout.com",