diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 545f11f..2b8e3b0 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -15,6 +15,7 @@ Yii Framework 2 Change Log
 - Bug #18526: Fix `yii\caching\DbCache` to work with MSSQL, add `normalizeTableRowData()` to `yii\db\mssql\QueryBuilder::upsert()` (darkdef)
 - Bug #14343: Fix `yii\test\ActiveFixture` to use model's DB connection instead of the default one (margori, bizley)
 - Bug #17631: Fix `yii\widgets\BaseListView` to properly render custom summary (sjaakp, bizley)
+- Bug #17203: Fix `yii\db\Connection` to persist customized `queryBuilder` configuration after the `close()` → `open()` cycle (silverfire)
 - Bug #18325: Fix `yii\db\pgsql\Schema` to respect non-default PgSQL schema name for data types (theonedemon, silverfire)
 
 
diff --git a/framework/db/Connection.php b/framework/db/Connection.php
index 2ea8224..be19d21 100644
--- a/framework/db/Connection.php
+++ b/framework/db/Connection.php
@@ -425,6 +425,15 @@ class Connection extends Component
     public $isSybase = false;
 
     /**
+     * @var array An array of [[setQueryBuilder()]] calls, holding the passed arguments.
+     * Is used to restore a QueryBuilder configuration after the connection close/open cycle.
+     *
+     * @see restoreQueryBuilderConfiguration()
+     * @since 2.0.42
+     */
+    private $_queryBuilderConfigurations = [];
+
+    /**
      * @var Transaction the currently active transaction
      */
     private $_transaction;
@@ -851,7 +860,10 @@ class Connection extends Component
             $config = !is_array($this->schemaMap[$driver]) ? ['class' => $this->schemaMap[$driver]] : $this->schemaMap[$driver];
             $config['db'] = $this;
 
-            return $this->_schema = Yii::createObject($config);
+            $this->_schema = Yii::createObject($config);
+            $this->restoreQueryBuilderConfiguration();
+
+            return $this->_schema;
         }
 
         throw new NotSupportedException("Connection does not support reading schema information for '$driver' DBMS.");
@@ -875,6 +887,25 @@ class Connection extends Component
     public function setQueryBuilder($value)
     {
         Yii::configure($this->getQueryBuilder(), $value);
+        $this->_queryBuilderConfigurations[] = $value;
+    }
+
+    /**
+     * Restores custom QueryBuilder configuration after the connection close/open cycle
+     *
+     * @since 2.0.42
+     */
+    private function restoreQueryBuilderConfiguration()
+    {
+        if ($this->_queryBuilderConfigurations === []) {
+            return;
+        }
+
+        $queryBuilderConfigurations = $this->_queryBuilderConfigurations;
+        $this->_queryBuilderConfigurations = [];
+        foreach ($queryBuilderConfigurations as $queryBuilderConfiguration) {
+            $this->setQueryBuilder($queryBuilderConfiguration);
+        }
     }
 
     /**
diff --git a/tests/framework/db/ConnectionTest.php b/tests/framework/db/ConnectionTest.php
index be5ed4e..2136e01 100644
--- a/tests/framework/db/ConnectionTest.php
+++ b/tests/framework/db/ConnectionTest.php
@@ -10,6 +10,9 @@ namespace yiiunit\framework\db;
 use Yii;
 use yii\base\InvalidConfigException;
 use yii\caching\ArrayCache;
+use yii\db\conditions\AndCondition;
+use yii\db\conditions\ExistsConditionBuilder;
+use yii\db\conditions\OrCondition;
 use yii\db\Connection;
 use yii\db\Transaction;
 
@@ -46,6 +49,50 @@ abstract class ConnectionTest extends DatabaseTestCase
         $connection->open();
     }
 
+    public function testQueryBuilderConfigurationAfterOpenClose()
+    {
+        $connection = $this->getConnection(false, false);
+        $connection->setQueryBuilder([
+            'expressionBuilders' => [
+                // Just a dumb mapping to make sure it's applied
+                'yii\db\conditions\OrCondition' => 'yii\db\conditions\ExistsConditionBuilder'
+            ],
+        ]);
+        // Second call to make sure that consecutive calls are handled correctly
+        $connection->setQueryBuilder([
+            'expressionBuilders' => [
+                'yii\db\conditions\AndCondition' => 'yii\db\conditions\InConditionBuilder'
+            ],
+        ]);
+
+        $orCondition = new OrCondition(['dumb']);
+        $andCondition = new AndCondition(['dumb']);
+
+        $connection->open();
+
+        $this->assertInstanceOf(
+            '\yii\db\conditions\ExistsConditionBuilder',
+            $connection->getQueryBuilder()->getExpressionBuilder($orCondition)
+        );
+        $this->assertInstanceOf(
+            '\yii\db\conditions\InConditionBuilder',
+            $connection->getQueryBuilder()->getExpressionBuilder($andCondition)
+        );
+
+        $connection->close();
+        $this->assertNull($connection->pdo);
+        $connection->open();
+
+        $this->assertInstanceOf(
+            '\yii\db\conditions\ExistsConditionBuilder',
+            $connection->getQueryBuilder()->getExpressionBuilder($orCondition)
+        );
+        $this->assertInstanceOf(
+            '\yii\db\conditions\InConditionBuilder',
+            $connection->getQueryBuilder()->getExpressionBuilder($andCondition)
+        );
+    }
+
     public function testSerialize()
     {
         $connection = $this->getConnection(false, false);