diff --git a/htdocs/product/class/api_products.class.php b/htdocs/product/class/api_products.class.php
index 2e12c1cb503..a1c0e3d8cb6 100644
--- a/htdocs/product/class/api_products.class.php
+++ b/htdocs/product/class/api_products.class.php
@@ -1872,7 +1872,7 @@ class Products extends DolibarrApi
 		}
 		
 		// product is used
-        $this->product->is_object_used = $this->product->isObjectUsed();
+        $this->product->is_object_used = $this->product->isObjectUsed() > 0;
 
 		return $this->_cleanObjectDatas($this->product);
 	}