diff --git a/htdocs/product/class/product.class.php b/htdocs/product/class/product.class.php
index 67002e48efb..db5ebf7bf4c 100644
--- a/htdocs/product/class/product.class.php
+++ b/htdocs/product/class/product.class.php
@@ -871,6 +871,7 @@ class Product extends CommonObject
 					$langs->load("products");
 					$error++;
 					$this->error = "ErrorProductAlreadyExists";
+					dol_syslog(get_class($this)."::Create fails, ref ".$this->ref." already exists");
 				}
 			} else {
 				$error++;
diff --git a/test/phpunit/MouvementStockTest.php b/test/phpunit/MouvementStockTest.php
index a781ea78e12..d084f50d6e0 100644
--- a/test/phpunit/MouvementStockTest.php
+++ b/test/phpunit/MouvementStockTest.php
@@ -146,41 +146,44 @@ class MouvementStockTest extends PHPUnit\Framework\TestCase
 		// We create a product for tests
 		$product0=new Product($db);
 		$product0->initAsSpecimen();
-		$product0->ref.=' 0';
-		$product0->label.=' 0';
+		$product0->ref.=' phpunit 0';
+		$product0->label.=' phpunit 0';
 		$product0->status_batch = 1;
 		$product0id=$product0->create($user);
 
+		print __METHOD__." product0id=".$product0id."\n";
+		$this->assertGreaterThan(0, $product0id, 'Failed to create product');
+
 		$product1=new Product($db);
 		$product1->initAsSpecimen();
-		$product1->ref.=' 1';
-		$product1->label.=' 1';
+		$product1->ref.=' phpunit 1';
+		$product1->label.=' phpunit 1';
 		$product1id=$product1->create($user);
 
 		$product2=new Product($db);
 		$product2->initAsSpecimen();
-		$product2->ref.=' 2';
-		$product2->label.=' 2';
+		$product2->ref.=' phpunit 2';
+		$product2->label.=' phpunit 2';
 		$product2id=$product2->create($user);
 
 		// We create a product for tests
 		$warehouse0=new Entrepot($db);
 		$warehouse0->initAsSpecimen();
-		$warehouse0->label.=' 0';
-		$warehouse0->description.=' 0';
+		$warehouse0->label.=' phpunit 0';
+		$warehouse0->description.=' phpunit 0';
 		$warehouse0->statut = 0;
 		$warehouse0id=$warehouse0->create($user);
 
 		$warehouse1=new Entrepot($db);
 		$warehouse1->initAsSpecimen();
-		$warehouse1->label.=' 1';
-		$warehouse1->description.=' 1';
+		$warehouse1->label.=' phpunit 1';
+		$warehouse1->description.=' phpunit 1';
 		$warehouse1id=$warehouse1->create($user);
 
 		$warehouse2=new Entrepot($db);
 		$warehouse2->initAsSpecimen();
-		$warehouse2->label.=' 2';
-		$warehouse2->description.=' 2';
+		$warehouse2->label.=' phpunit 2';
+		$warehouse2->description.=' phpunit 2';
 		$warehouse2id=$warehouse2->create($user);
 
 		$localobject=new MouvementStock($this->savdb);
@@ -188,10 +191,10 @@ class MouvementStockTest extends PHPUnit\Framework\TestCase
 		$datetest1 = dol_mktime(0, 0, 0, 1, 1, 2000);
 		$datetest2 = dol_mktime(0, 0, 0, 1, 2, 2000);
 
-		// Create an input movement movement (type = 3) with value for eatby date and a lot
+		// Create an input movement movement (type = 3) with value for eatby date and a lot $datetest1
 		$result=$localobject->reception($user, $product0id, $warehouse0id, 5, 999, 'Movement for unit test with batch', $datetest1, $datetest1, 'anotyetuselotnumberA', '', 0, 'Inventory Code Test with batch');
 		print __METHOD__." result=".$result."\n";
-		$this->assertGreaterThan(0, $result, 'Failed to create a movement with a lot number of product with status_batch=1');
+		$this->assertGreaterThan(0, $result, 'Failed to create a movement with a lot number '.$datetest1.' for product id='.$product0id.' with status_batch=1');
 
 		$result=$localobject->reception($user, $product0id, $warehouse0id, 5, 999, 'Movement for unit test with batch', $datetest1, $datetest1, 'anotyetuselotnumberB', '', 0, 'Inventory Code Test with batch');
 		print __METHOD__." result=".$result."\n";
@@ -250,12 +253,12 @@ class MouvementStockTest extends PHPUnit\Framework\TestCase
 		// Create an output movement (type = 1) of price 9.7 -> should update PMP to 9.9/9.7 = 9.8
 		$result=$localobject->_create($user, $product1id, $warehouse2id, 1, 0, 0, 'Input from transfer wh 2', 'Transfert X 2');
 		print __METHOD__." result=".$result."\n";
-		$this->assertGreaterThan(0, $result);
+		$this->assertGreaterThan(0, $result, 'Test create A');
 
 		// Create an output movement (type = 1) of price 9.7 -> should update PMP to 9.9/9.7 = 9.8
 		$result=$localobject->_create($user, $product1id, $warehouse2id, -2, 1, 0, 'Output from transfer wh 2', 'Transfert Y 2');
 		print __METHOD__." result=".$result."\n";
-		$this->assertGreaterThan(0, $result);
+		$this->assertGreaterThan(0, $result, 'Test create B');
 
 		return $localobject;
 	}