diff --git a/adminer/select.inc.php b/adminer/select.inc.php
index 51720960..9fe71ec0 100644
--- a/adminer/select.inc.php
+++ b/adminer/select.inc.php
@@ -24,6 +24,8 @@ foreach ($fields as $key => $field) {
 }
 
 list($select, $group) = $adminer->selectColumnsProcess($columns, $indexes);
+$select = array_unique($select);
+$group = array_unique($group);
 $is_group = count($group) < count($select);
 $where = $adminer->selectSearchProcess($fields, $indexes);
 $order = $adminer->selectOrderProcess($fields, $indexes);
diff --git a/changes.txt b/changes.txt
index fc5994b5..3fafdd15 100644
--- a/changes.txt
+++ b/changes.txt
@@ -1,4 +1,5 @@
 Adminer dev:
+Remove duplicate columns from select (bug #670)
 MariaDB: Fix link to status variable doc (bug #658)
 
 Adminer 5.0.0 (released 2025-03-07):