diff --git a/conf/datasources.ini.sample b/conf/datasources.ini.sample
index 1e1284f9..4155bece 100644
--- a/conf/datasources.ini.sample
+++ b/conf/datasources.ini.sample
@@ -191,6 +191,7 @@
 ;; unsuppressed to suppressed won't be detected.
 ;;suppressedRecords = false
 ;suppressedBibCode3 = 'c,d,n'
+;keepExisting852Fields = false
 ;institution = SierraLib
 ;format = marc
 ;dedup = true
diff --git a/src/RecordManager/Base/Harvest/SierraApi.php b/src/RecordManager/Base/Harvest/SierraApi.php
index 6854753c..858a6b69 100644
--- a/src/RecordManager/Base/Harvest/SierraApi.php
+++ b/src/RecordManager/Base/Harvest/SierraApi.php
@@ -108,6 +108,14 @@ class SierraApi extends AbstractBase
      */
     protected $suppressedBibCode3 = [];
 
+    /**
+     * Whether to keep existing 852 fields in the MARC records before adding new ones
+     * for the item locations.
+     *
+     * @var bool
+     */
+    protected $keepExisting852Fields = false;
+
     /**
      * HTTP client options
      *
@@ -154,7 +162,8 @@ public function init(string $source, bool $verbose, bool $reharvest): void
             ',',
             $settings['suppressedBibCode3'] ?? ''
         );
-        $this->apiVersion = 'v' . ($settings['sierraApiVersion'] ?? '5');
+        $this->apiVersion = 'v' . ($settings['sierraApiVersion'] ?? '6');
+        $this->keepExisting852Fields = $settings['keepExisting852Fields'] ?? false;
     }
 
     /**
@@ -540,7 +549,10 @@ protected function convertRecordToMarcArray($record)
                 $marc['leader'] = $varField['content'];
                 continue;
             }
-            if (!isset($varField['marcTag']) || $varField['marcTag'] == '852') {
+            if (
+                !isset($varField['marcTag'])
+                || (!$this->keepExisting852Fields && $varField['marcTag'] == '852')
+            ) {
                 continue;
             }
             // Make sure the tag has three characters