diff --git a/CHANGELOG.MD b/CHANGELOG.MD
index 5bb9fecf..19fa5f34 100644
--- a/CHANGELOG.MD
+++ b/CHANGELOG.MD
@@ -4,6 +4,13 @@
 ...
 
 
+## [1.25.0] (2020.11.04)
+
+### Fixed
+- Improved Customer and Product Tax Class fetcher for Tax Rules ([#354](https://github.com/DivanteLtd/magento2-vsbridge-indexer/issues/353))
+
+## [1.24.0]
+
 ## [1.23.0] (2020.11.03)
 
 ### Fixed
diff --git a/src/module-vsbridge-indexer-tax/Model/Indexer/DataProvider/TaxClasses.php b/src/module-vsbridge-indexer-tax/Model/Indexer/DataProvider/TaxClasses.php
index b8bfc239..61487ec4 100644
--- a/src/module-vsbridge-indexer-tax/Model/Indexer/DataProvider/TaxClasses.php
+++ b/src/module-vsbridge-indexer-tax/Model/Indexer/DataProvider/TaxClasses.php
@@ -40,10 +40,19 @@ public function addData(array $indexData, $storeId)
 
         foreach ($taxClasses as $data) {
             $ruleId = $data['tax_calculation_rule_id'];
-            $indexData[$ruleId]['customer_tax_class_ids'][] = (int)$data['customer_tax_class_id'];
-            $indexData[$ruleId]['product_tax_class_ids'][] = (int)$data['product_tax_class_id'];
+            $indexData[$ruleId]['customer_tax_class_ids'] = $this->explodeAsInt($data['customer_tax_class_ids']);
+            $indexData[$ruleId]['product_tax_class_ids'] = $this->explodeAsInt($data['product_tax_class_ids']);
         }
 
         return $indexData;
     }
+
+    /**
+     * @param string $concatIds
+     * @return array
+     */
+    protected function explodeAsInt(string $concatIds) : array
+    {
+        return array_map('intval', explode(',', $concatIds));
+    }
 }
diff --git a/src/module-vsbridge-indexer-tax/ResourceModel/TaxClasses.php b/src/module-vsbridge-indexer-tax/ResourceModel/TaxClasses.php
index d5ed75b7..2952e05e 100644
--- a/src/module-vsbridge-indexer-tax/ResourceModel/TaxClasses.php
+++ b/src/module-vsbridge-indexer-tax/ResourceModel/TaxClasses.php
@@ -43,12 +43,11 @@ public function loadTaxClasses(array $ruleIds)
             $this->resource->getTableName('tax_calculation'),
             [
                 'tax_calculation_rule_id',
-                'customer_tax_class_id',
-                'product_tax_class_id',
+                'customer_tax_class_ids' => new \Zend_Db_Expr('GROUP_CONCAT(DISTINCT(`customer_tax_class_id`))'),
+                'product_tax_class_ids' => new \Zend_Db_Expr('GROUP_CONCAT(DISTINCT(`product_tax_class_id`))'),
             ]
-        )->where('tax_calculation_rule_id IN (?)', $ruleIds);
-
-        $select->distinct(true);
+        )->where('tax_calculation_rule_id IN (?)', $ruleIds
+        )->group('tax_calculation_rule_id');
 
         return $this->getConnection()->fetchAssoc($select);
     }