diff --git a/dblayer.php b/dblayer.php
index 74279aa..f7f9073 100644
--- a/dblayer.php
+++ b/dblayer.php
@@ -378,8 +378,14 @@ class dblayer extends PDO
     {
       if ($this->debug) echo "   verify NO updatekey\n";
       $after = $datasOK;
+
     }
     // Check if the unique constrain is valid before doing the insertion
+    if ($this->unique === null && $this->primary !== null)
+      $this->unique = array ($this->primary);
+    // TODO : If Unique is not defined nor primary
+    // FIXME : If unique is defined, could I test if the primary key is defined
+    // in a parameter of the unique and if it is not add it automatically 
     foreach ($this->unique as $k=>$columns)
     {
       if ($this->primary === null)