diff --git a/backend/src/api/blocks.ts b/backend/src/api/blocks.ts
index ba4dfa8bd..b95756ae5 100644
--- a/backend/src/api/blocks.ts
+++ b/backend/src/api/blocks.ts
@@ -566,7 +566,7 @@ class Blocks {
    */
   public async $classifyBlocks(): Promise<void> {
     // classification requires an esplora backend
-    if (config.MEMPOOL.BACKEND !== 'esplora') {
+    if (!Common.blocksSummariesIndexingEnabled() || config.MEMPOOL.BACKEND !== 'esplora') {
       return;
     }
 
@@ -577,7 +577,7 @@ class Blocks {
     const unclassifiedTemplatesList = await BlocksSummariesRepository.$getTemplatesWithVersion(0);
 
     // nothing to do
-    if (!unclassifiedBlocksList.length && !unclassifiedTemplatesList.length) {
+    if (!unclassifiedBlocksList?.length && !unclassifiedTemplatesList?.length) {
       return;
     }
 
@@ -586,8 +586,8 @@ class Blocks {
     let indexedTotal = 0;
 
     const minHeight = Math.min(
-      unclassifiedBlocksList[unclassifiedBlocksList.length - 1].height ?? Infinity,
-      unclassifiedTemplatesList[unclassifiedTemplatesList.length - 1].height ?? Infinity,
+      unclassifiedBlocksList[unclassifiedBlocksList.length - 1]?.height ?? Infinity,
+      unclassifiedTemplatesList[unclassifiedTemplatesList.length - 1]?.height ?? Infinity,
     );
     const numToIndex = Math.max(
       unclassifiedBlocksList.length,
diff --git a/backend/src/api/database-migration.ts b/backend/src/api/database-migration.ts
index e83ad4536..162616af6 100644
--- a/backend/src/api/database-migration.ts
+++ b/backend/src/api/database-migration.ts
@@ -559,7 +559,7 @@ class DatabaseMigration {
       await this.updateToSchemaVersion(66);
     }
 
-    if (databaseSchemaVersion < 67) {
+    if (databaseSchemaVersion < 67  && isBitcoin === true) {
       await this.$executeQuery('ALTER TABLE `blocks_summaries` ADD version INT NOT NULL DEFAULT 0');
       await this.$executeQuery('ALTER TABLE `blocks_summaries` ADD INDEX `version` (`version`)');
       await this.$executeQuery('ALTER TABLE `blocks_templates` ADD version INT NOT NULL DEFAULT 0');