diff --git a/.phpstan-dba.cache b/.phpstan-dba.cache
index 9cba86f9c..87120bf9a 100644
--- a/.phpstan-dba.cache
+++ b/.phpstan-dba.cache
@@ -5895,6 +5895,155 @@ Simulated query: SELECT email, adaid, gesperrt, freigabe1u1 FROM ada . WHERE ema
         3 => NULL,
       ),
     ),
+    'SELECT email, adaid, gesperrt, freigabe1u1 FROM ada WHERE email = \'1\'' => 
+    array (
+      'error' => NULL,
+      'result' => 
+      array (
+        5 => 
+        PHPStan\Type\Constant\ConstantArrayType::__set_state(array(
+           'allArrays' => NULL,
+           'keyTypes' => 
+          array (
+            0 => 
+            PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+               'value' => 'email',
+               'isClassString' => false,
+            )),
+            1 => 
+            PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+               'value' => 0,
+            )),
+            2 => 
+            PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+               'value' => 'adaid',
+               'isClassString' => false,
+            )),
+            3 => 
+            PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+               'value' => 1,
+            )),
+            4 => 
+            PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+               'value' => 'gesperrt',
+               'isClassString' => false,
+            )),
+            5 => 
+            PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+               'value' => 2,
+            )),
+            6 => 
+            PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+               'value' => 'freigabe1u1',
+               'isClassString' => false,
+            )),
+            7 => 
+            PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+               'value' => 3,
+            )),
+          ),
+           'valueTypes' => 
+          array (
+            0 => 
+            PHPStan\Type\StringType::__set_state(array(
+            )),
+            1 => 
+            PHPStan\Type\StringType::__set_state(array(
+            )),
+            2 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => 0,
+               'max' => 4294967295,
+            )),
+            3 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => 0,
+               'max' => 4294967295,
+            )),
+            4 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => -128,
+               'max' => 127,
+            )),
+            5 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => -128,
+               'max' => 127,
+            )),
+            6 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => -128,
+               'max' => 127,
+            )),
+            7 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => -128,
+               'max' => 127,
+            )),
+          ),
+           'nextAutoIndex' => 4,
+           'optionalKeys' => 
+          array (
+          ),
+           'keyType' => 
+          PHPStan\Type\UnionType::__set_state(array(
+             'types' => 
+            array (
+              0 => 
+              PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+                 'value' => 0,
+              )),
+              1 => 
+              PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+                 'value' => 1,
+              )),
+              2 => 
+              PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+                 'value' => 2,
+              )),
+              3 => 
+              PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+                 'value' => 3,
+              )),
+              4 => 
+              PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+                 'value' => 'adaid',
+                 'isClassString' => false,
+              )),
+              5 => 
+              PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+                 'value' => 'email',
+                 'isClassString' => false,
+              )),
+              6 => 
+              PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+                 'value' => 'freigabe1u1',
+                 'isClassString' => false,
+              )),
+              7 => 
+              PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+                 'value' => 'gesperrt',
+                 'isClassString' => false,
+              )),
+            ),
+          )),
+           'itemType' => 
+          PHPStan\Type\UnionType::__set_state(array(
+             'types' => 
+            array (
+              0 => 
+              PHPStan\Type\IntegerRangeType::__set_state(array(
+                 'min' => -128,
+                 'max' => 4294967295,
+              )),
+              1 => 
+              PHPStan\Type\StringType::__set_state(array(
+              )),
+            ),
+          )),
+        )),
+      ),
+    ),
     'SELECT email, adaid, gesperrt, freigabe1u1 FROM ada WHERE email = \'test@example.org\'' => 
     array (
       'error' => NULL,
diff --git a/.phpunit-phpstan-dba.cache b/.phpunit-phpstan-dba.cache
index fcdc96136..b094ca3c7 100644
--- a/.phpunit-phpstan-dba.cache
+++ b/.phpunit-phpstan-dba.cache
@@ -4239,6 +4239,155 @@ Simulated query: SELECT email, adaid, gesperrt, freigabe1u1 FROM ada . WHERE ema
          'code' => 1064,
       )),
     ),
+    'SELECT email, adaid, gesperrt, freigabe1u1 FROM ada WHERE email = \'1\'' => 
+    array (
+      'error' => NULL,
+      'result' => 
+      array (
+        5 => 
+        PHPStan\Type\Constant\ConstantArrayType::__set_state(array(
+           'allArrays' => NULL,
+           'keyTypes' => 
+          array (
+            0 => 
+            PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+               'value' => 'email',
+               'isClassString' => false,
+            )),
+            1 => 
+            PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+               'value' => 0,
+            )),
+            2 => 
+            PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+               'value' => 'adaid',
+               'isClassString' => false,
+            )),
+            3 => 
+            PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+               'value' => 1,
+            )),
+            4 => 
+            PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+               'value' => 'gesperrt',
+               'isClassString' => false,
+            )),
+            5 => 
+            PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+               'value' => 2,
+            )),
+            6 => 
+            PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+               'value' => 'freigabe1u1',
+               'isClassString' => false,
+            )),
+            7 => 
+            PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+               'value' => 3,
+            )),
+          ),
+           'valueTypes' => 
+          array (
+            0 => 
+            PHPStan\Type\StringType::__set_state(array(
+            )),
+            1 => 
+            PHPStan\Type\StringType::__set_state(array(
+            )),
+            2 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => 0,
+               'max' => 4294967295,
+            )),
+            3 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => 0,
+               'max' => 4294967295,
+            )),
+            4 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => -128,
+               'max' => 127,
+            )),
+            5 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => -128,
+               'max' => 127,
+            )),
+            6 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => -128,
+               'max' => 127,
+            )),
+            7 => 
+            PHPStan\Type\IntegerRangeType::__set_state(array(
+               'min' => -128,
+               'max' => 127,
+            )),
+          ),
+           'nextAutoIndex' => 4,
+           'optionalKeys' => 
+          array (
+          ),
+           'keyType' => 
+          PHPStan\Type\UnionType::__set_state(array(
+             'types' => 
+            array (
+              0 => 
+              PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+                 'value' => 0,
+              )),
+              1 => 
+              PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+                 'value' => 1,
+              )),
+              2 => 
+              PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+                 'value' => 2,
+              )),
+              3 => 
+              PHPStan\Type\Constant\ConstantIntegerType::__set_state(array(
+                 'value' => 3,
+              )),
+              4 => 
+              PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+                 'value' => 'adaid',
+                 'isClassString' => false,
+              )),
+              5 => 
+              PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+                 'value' => 'email',
+                 'isClassString' => false,
+              )),
+              6 => 
+              PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+                 'value' => 'freigabe1u1',
+                 'isClassString' => false,
+              )),
+              7 => 
+              PHPStan\Type\Constant\ConstantStringType::__set_state(array(
+                 'value' => 'gesperrt',
+                 'isClassString' => false,
+              )),
+            ),
+          )),
+           'itemType' => 
+          PHPStan\Type\UnionType::__set_state(array(
+             'types' => 
+            array (
+              0 => 
+              PHPStan\Type\IntegerRangeType::__set_state(array(
+                 'min' => -128,
+                 'max' => 4294967295,
+              )),
+              1 => 
+              PHPStan\Type\StringType::__set_state(array(
+              )),
+            ),
+          )),
+        )),
+      ),
+    ),
     'SELECT email, adaid, gesperrt, freigabe1u1 FROM ada WHERE email = \'test@example.org\'' => 
     array (
       'error' => NULL,
diff --git a/src/QueryReflection/QuerySimulation.php b/src/QueryReflection/QuerySimulation.php
index 0460e6379..5bf7397de 100644
--- a/src/QueryReflection/QuerySimulation.php
+++ b/src/QueryReflection/QuerySimulation.php
@@ -13,12 +13,14 @@
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\MixedType;
+use PHPStan\Type\ObjectType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
 use staabm\PHPStanDba\DbaException;
 use staabm\PHPStanDba\UnresolvableQueryException;
+use Stringable;
 
 /**
  * @internal
@@ -70,7 +72,7 @@ public static function simulateParamValueType(Type $paramType, bool $preparedPar
         }
 
         $stringType = new StringType();
-        if ($stringType->isSuperTypeOf($paramType)->yes()) {
+        if ($stringType->isSuperTypeOf($paramType)->yes() || $paramType instanceof ObjectType && $paramType->isInstanceOf(Stringable::class)->yes()) {
             // in a prepared context, regular strings are fine
             if (true === $preparedParam) {
                 return '1';
diff --git a/tests/Fixture/StringableObject.php b/tests/Fixture/StringableObject.php
new file mode 100644
index 000000000..480bf83f2
--- /dev/null
+++ b/tests/Fixture/StringableObject.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace staabm\PHPStanDba\Tests\Fixture;
+
+class StringableObject
+{
+    public function __toString()
+    {
+        return 'foo';
+    }
+}
diff --git a/tests/data/doctrine-dbal.php b/tests/data/doctrine-dbal.php
index 9ca8a985b..777453618 100644
--- a/tests/data/doctrine-dbal.php
+++ b/tests/data/doctrine-dbal.php
@@ -5,6 +5,7 @@
 use Doctrine\DBAL\Cache\QueryCacheProfile;
 use Doctrine\DBAL\Connection;
 use function PHPStan\Testing\assertType;
+use staabm\PHPStanDba\Tests\Fixture\StringableObject;
 
 class Foo
 {
@@ -149,4 +150,11 @@ public function fetchAllKeyValue(Connection $conn)
         $fetchResult = $conn->fetchAllKeyValue($query, [1]);
         assertType('array<string, int<0, 4294967295>>', $fetchResult);
     }
+
+    public function fetchStringable(Connection $conn)
+    {
+        $query = 'SELECT email, adaid, gesperrt, freigabe1u1 FROM ada WHERE email = ?';
+        $fetchResult = $conn->fetchAllKeyValue($query, [new StringableObject()]);
+        assertType('array<string, int<0, 4294967295>>', $fetchResult);
+    }
 }