diff --git a/api/database.php b/api/database.php
index df8a8fb..601e856 100644
--- a/api/database.php
+++ b/api/database.php
@@ -515,6 +515,28 @@ if (empty($recipeTagsTables)) {
         ('brunch', 'Brunch', '🥂', 23)
     ");
 }
+// Custom quantity units (v2.4) — unités personnalisées (ex: kg, L) avec facteur de conversion vers pz/g/ml, gérables depuis Config
+$customUnitsTables = $db->query("SELECT name FROM sqlite_master WHERE type='table' AND name='custom_units'")->fetchAll();
+if (empty($customUnitsTables)) {
+    $db->exec("
+        CREATE TABLE custom_units (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            key TEXT UNIQUE NOT NULL,
+            label TEXT NOT NULL,
+            icon TEXT DEFAULT '📏',
+            base_unit TEXT NOT NULL DEFAULT 'g',
+            factor REAL NOT NULL DEFAULT 1,
+            sort_order INTEGER DEFAULT 0
+        );
+    ");
+}
+// Add display_unit_key column to products if missing — unité personnalisée a afficher pour ce produit
+$prodColsUnits = array_column($db->query("PRAGMA table_info(products)")->fetchAll(), 'name');
+if (!in_array('display_unit_key', $prodColsUnits)) {
+    try { $db->exec("ALTER TABLE products ADD COLUMN display_unit_key TEXT DEFAULT NULL"); }
+    catch (PDOException $e) { if (strpos($e->getMessage(), 'duplicate column') === false) throw $e; }
+}
+    // Internal shopping list table (v1.8.0) — used when SHOPPING_MODE=internal
     
     // Internal shopping list table (v1.8.0) — used when SHOPPING_MODE=internal
     $shopTables = $db->query("SELECT name FROM sqlite_master WHERE type='table' AND name='shopping_list'")->fetchAll();