diff --git a/src/Schema/Visitor/DropSchemaSqlCollector.php b/src/Schema/Visitor/DropSchemaSqlCollector.php
index ddec6b4aed1..d746b2aee66 100644
--- a/src/Schema/Visitor/DropSchemaSqlCollector.php
+++ b/src/Schema/Visitor/DropSchemaSqlCollector.php
@@ -42,7 +42,7 @@ public function __construct(AbstractPlatform $platform)
      */
     public function acceptTable(Table $table)
     {
-        $this->tables->attach($table);
+        $this->tables->offsetSet($table);
     }
 
     /**
@@ -54,7 +54,7 @@ public function acceptForeignKey(Table $localTable, ForeignKeyConstraint $fkCons
             throw SchemaException::namedForeignKeyRequired($localTable, $fkConstraint);
         }
 
-        $this->constraints->attach($fkConstraint, $localTable);
+        $this->constraints->offsetSet($fkConstraint, $localTable);
     }
 
     /**
@@ -62,7 +62,7 @@ public function acceptForeignKey(Table $localTable, ForeignKeyConstraint $fkCons
      */
     public function acceptSequence(Sequence $sequence)
     {
-        $this->sequences->attach($sequence);
+        $this->sequences->offsetSet($sequence);
     }
 
     /** @return void */