diff --git a/src/Symfony/Component/Validator/Constraints/FileValidator.php b/src/Symfony/Component/Validator/Constraints/FileValidator.php
index 62a6139a6efb9..05f73b7497950 100644
--- a/src/Symfony/Component/Validator/Constraints/FileValidator.php
+++ b/src/Symfony/Component/Validator/Constraints/FileValidator.php
@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Validator\Constraints;
 
+use Psr\Http\Message\UploadedFileInterface;
 use Symfony\Component\HttpFoundation\File\File as FileObject;
 use Symfony\Component\HttpFoundation\File\UploadedFile;
 use Symfony\Component\Validator\Context\ExecutionContextInterface;
@@ -51,10 +52,18 @@ public function validate($value, Constraint $constraint)
             return;
         }
 
-        if ($value instanceof UploadedFile && !$value->isValid()) {
-            switch ($value->getError()) {
+        $error = null;
+        if (
+            ($value instanceof UploadedFile && !$value->isValid())
+            || ($value instanceof UploadedFileInterface && UPLOAD_ERR_OK !== $value->getError())
+        ) {
+            $error = $value->getError();
+        }
+
+        if (null !== $error) {
+            switch ($error) {
                 case UPLOAD_ERR_INI_SIZE:
-                    $iniLimitSize = UploadedFile::getMaxFilesize();
+                    $iniLimitSize = self::getMaxFilesize();
                     if ($constraint->maxSize && $constraint->maxSize < $iniLimitSize) {
                         $limitInBytes = $constraint->maxSize;
                         $binaryFormat = $constraint->binaryFormat;
@@ -154,11 +163,11 @@ public function validate($value, Constraint $constraint)
                 default:
                     if ($this->context instanceof ExecutionContextInterface) {
                         $this->context->buildViolation($constraint->uploadErrorMessage)
-                            ->setCode($value->getError())
+                            ->setCode($error)
                             ->addViolation();
                     } else {
                         $this->buildViolation($constraint->uploadErrorMessage)
-                            ->setCode($value->getError())
+                            ->setCode($error)
                             ->addViolation();
                     }
 
@@ -166,6 +175,12 @@ public function validate($value, Constraint $constraint)
             }
         }
 
+        if ($value instanceof UploadedFileInterface) {
+            // PSR-7 UploadedFileInterface does not represent a file
+            // in the filesystem.
+            return;
+        }
+
         if (!is_scalar($value) && !$value instanceof FileObject && !(is_object($value) && method_exists($value, '__toString'))) {
             throw new UnexpectedTypeException($value, 'string');
         }
@@ -292,6 +307,33 @@ private static function moreDecimalsThan($double, $numberOfDecimals)
         return strlen((string) $double) > strlen(round($double, $numberOfDecimals));
     }
 
+    private static function getMaxFilesize()
+    {
+        $iniMax = strtolower(ini_get('upload_max_filesize'));
+
+        if ('' === $iniMax) {
+            return PHP_INT_MAX;
+        }
+
+        $max = ltrim($iniMax, '+');
+        if (0 === strpos($max, '0x')) {
+            $max = intval($max, 16);
+        } elseif (0 === strpos($max, '0')) {
+            $max = intval($max, 8);
+        } else {
+            $max = (int) $max;
+        }
+
+        switch (substr($iniMax, -1)) {
+            case 't': $max *= 1024;
+            case 'g': $max *= 1024;
+            case 'm': $max *= 1024;
+            case 'k': $max *= 1024;
+        }
+
+        return $max;
+    }
+
     /**
      * Convert the limit to the smallest possible number
      * (i.e. try "MB", then "kB", then "bytes").
diff --git a/src/Symfony/Component/Validator/Tests/Constraints/FileValidatorPsr7Test.php b/src/Symfony/Component/Validator/Tests/Constraints/FileValidatorPsr7Test.php
new file mode 100644
index 0000000000000..003657658f50b
--- /dev/null
+++ b/src/Symfony/Component/Validator/Tests/Constraints/FileValidatorPsr7Test.php
@@ -0,0 +1,49 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Validator\Tests\Constraints;
+
+use Symfony\Component\Validator\Constraints\File;
+use Symfony\Component\Validator\Constraints\FileValidator;
+
+class FileValidatorPsr7Test extends AbstractConstraintValidatorTest
+{
+    protected function createValidator()
+    {
+        return new FileValidator();
+    }
+
+    public function testValidUploadedFile()
+    {
+        $file = $this->getMock('Psr\Http\Message\UploadedFileInterface');
+        $file->expects($this->any())->method('getError')->willReturn(UPLOAD_ERR_OK);
+
+        $this->validator->validate($file, new File());
+
+        $this->assertNoViolation();
+    }
+
+    public function testInvalidUploadedFile()
+    {
+        $file = $this->getMock('Psr\Http\Message\UploadedFileInterface');
+        $file->expects($this->any())->method('getError')->willReturn(UPLOAD_ERR_FORM_SIZE);
+
+        $constraint = new File(array(
+            'uploadFormSizeErrorMessage' => 'myMessage',
+        ));
+
+        $this->validator->validate($file, $constraint);
+
+        $this->buildViolation('myMessage')
+            ->setCode(UPLOAD_ERR_FORM_SIZE)
+            ->assertRaised();
+    }
+}
diff --git a/src/Symfony/Component/Validator/composer.json b/src/Symfony/Component/Validator/composer.json
index 2208bc9a76844..b622343c630c0 100644
--- a/src/Symfony/Component/Validator/composer.json
+++ b/src/Symfony/Component/Validator/composer.json
@@ -29,7 +29,8 @@
         "symfony/expression-language": "~2.4|~3.0.0",
         "doctrine/annotations": "~1.0",
         "doctrine/cache": "~1.0",
-        "egulias/email-validator": "~1.2,>=1.2.1"
+        "egulias/email-validator": "~1.2,>=1.2.1",
+        "psr/http-message": "~1.0"
     },
     "suggest": {
         "doctrine/annotations": "For using the annotation mapping. You will also need doctrine/cache.",
@@ -40,7 +41,8 @@
         "symfony/config": "",
         "egulias/email-validator": "Strict (RFC compliant) email validation",
         "symfony/property-access": "For using the 2.4 Validator API",
-        "symfony/expression-language": "For using the 2.4 Expression validator"
+        "symfony/expression-language": "For using the 2.4 Expression validator",
+        "psr/http-message": "For validating PSR-7 UploadedFileInterface implementations"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Validator\\": "" }