diff --git a/htdocs/install/upgrade.php b/htdocs/install/upgrade.php
index 58e0bf1bc0f..271c5d8125b 100644
--- a/htdocs/install/upgrade.php
+++ b/htdocs/install/upgrade.php
@@ -238,45 +238,51 @@ if (! GETPOST("action") || preg_match('/upgrade/i',GETPOST('action')))
 			&& versioncompare($versioncommande,$versionarray) <= 0)	// Si mysql >= 4.0
 		{
 			// Suppression vieilles contraintes sans noms et en doubles
-			// Les contraintes indesirables ont un nom qui commence par 0_ ou se termine par ibfk_999
-			$listtables=array(  'llx_adherent_options',
-								'llx_bank_class',
-								'llx_c_ecotaxe',
-								'llx_c_methode_commande_fournisseur',   // table renamed
-    		                    'llx_c_input_method');
-
-			$listtables = $db->DDLListTables($conf->db->name,'');
-		    foreach ($listtables as $val)
-			{
-				//print "x".$val."<br>";
-				$sql = "SHOW CREATE TABLE ".$val;
-				$resql = $db->query($sql);
-				if ($resql)
-				{
-					$values=$db->fetch_array($resql);
-					$i=0;
-					$createsql=$values[1];
-					while (preg_match('/CONSTRAINT `(0_[0-9a-zA-Z]+|[_0-9a-zA-Z]+_ibfk_[0-9]+)`/i',$createsql,$reg) && $i < 100)
-					{
-						$sqldrop="ALTER TABLE ".$val." DROP FOREIGN KEY ".$reg[1];
-						$resqldrop = $db->query($sqldrop);
-						if ($resqldrop)
-						{
-							print '<tr><td colspan="2">'.$sqldrop.";</td></tr>\n";
-						}
-						$createsql=preg_replace('/CONSTRAINT `'.$reg[1].'`/i','XXX',$createsql);
-						$i++;
-					}
-					$db->free($resql);
-				}
-				else
-				{
-					if ($db->lasterrno() != 'DB_ERROR_NOSUCHTABLE')
-					{
-						print '<tr><td colspan="2"><font  class="error">'.$sql.' : '.$db->lasterror()."</font></td></tr>\n";
-					}
-				}
-			}
+            // Les contraintes indesirables ont un nom qui commence par 0_ ou se termine par ibfk_999
+            $listtables=array(
+            					MAIN_DB_PREFIX.'adherent_options',
+            					MAIN_DB_PREFIX.'bank_class',
+            					MAIN_DB_PREFIX.'c_ecotaxe',
+            					MAIN_DB_PREFIX.'c_methode_commande_fournisseur',   // table renamed
+    		                    MAIN_DB_PREFIX.'c_input_method'
+            );
+            
+            $listtables = $db->DDLListTables($conf->db->name,'');
+            foreach ($listtables as $val)
+            {
+            	// Database prefix filter
+            	if (preg_match('/^'.MAIN_DB_PREFIX.'/', $val))
+            	{
+            		//print "x".$val."<br>";
+            		$sql = "SHOW CREATE TABLE ".$val;
+            		$resql = $db->query($sql);
+            		if ($resql)
+            		{
+            			$values=$db->fetch_array($resql);
+            			$i=0;
+            			$createsql=$values[1];
+            			while (preg_match('/CONSTRAINT `(0_[0-9a-zA-Z]+|[_0-9a-zA-Z]+_ibfk_[0-9]+)`/i',$createsql,$reg) && $i < 100)
+            			{
+            				$sqldrop="ALTER TABLE ".$val." DROP FOREIGN KEY ".$reg[1];
+            				$resqldrop = $db->query($sqldrop);
+            				if ($resqldrop)
+            				{
+            					print '<tr><td colspan="2">'.$sqldrop.";</td></tr>\n";
+            				}
+            				$createsql=preg_replace('/CONSTRAINT `'.$reg[1].'`/i','XXX',$createsql);
+            				$i++;
+            			}
+            			$db->free($resql);
+            		}
+            		else
+            		{
+            			if ($db->lasterrno() != 'DB_ERROR_NOSUCHTABLE')
+            			{
+            				print '<tr><td colspan="2"><font  class="error">'.$sql.' : '.$db->lasterror()."</font></td></tr>\n";
+            			}
+            		}
+            	}
+            }
 		}
 	}