diff --git a/src/Symfony/Component/Routing/RouteCompiler.php b/src/Symfony/Component/Routing/RouteCompiler.php
index f6637da666b8..1ce18ceb6607 100644
--- a/src/Symfony/Component/Routing/RouteCompiler.php
+++ b/src/Symfony/Component/Routing/RouteCompiler.php
@@ -28,12 +28,22 @@ class RouteCompiler implements RouteCompilerInterface
      */
     const SEPARATORS = '/,;.:-_~+*=@|';
 
+    /**
+     * The maximum supported length of a PCRE subpattern name
+     * http://pcre.org/current/doc/html/pcre2pattern.html#SEC16.
+     *
+     * @var int
+     *
+     * @internal
+     */
+    const VARIABLE_MAXIMUM_LENGTH = 32;
+
     /**
      * {@inheritdoc}
      *
      * @throws \LogicException  If a variable is referenced more than once
-     * @throws \DomainException If a variable name is numeric because PHP raises an error for such
-     *                          subpatterns in PCRE and thus would break matching, e.g. "(?P<123>.+)".
+     * @throws \DomainException If a variable name starts with a digit or if it is too long to be successfully used as
+     *                          a PCRE subpattern.
      */
     public static function compile(Route $route)
     {
@@ -95,13 +105,19 @@ private static function compilePattern(Route $route, $pattern, $isHost)
             $precedingChar = strlen($precedingText) > 0 ? substr($precedingText, -1) : '';
             $isSeparator = '' !== $precedingChar && false !== strpos(static::SEPARATORS, $precedingChar);
 
-            if (is_numeric($varName)) {
-                throw new \DomainException(sprintf('Variable name "%s" cannot be numeric in route pattern "%s". Please use a different name.', $varName, $pattern));
+            // A PCRE subpattern name must start with a non-digit. Also a PHP variable cannot start with a digit so the
+            // variable would not be usable as a Controller action argument.
+            if (preg_match('/^\d/', $varName)) {
+                throw new \DomainException(sprintf('Variable name "%s" cannot start with a digit in route pattern "%s". Please use a different name.', $varName, $pattern));
             }
             if (in_array($varName, $variables)) {
                 throw new \LogicException(sprintf('Route pattern "%s" cannot reference variable name "%s" more than once.', $pattern, $varName));
             }
 
+            if (strlen($varName) > self::VARIABLE_MAXIMUM_LENGTH) {
+                throw new \DomainException(sprintf('Variable name "%s" cannot be longer than %s characters in route pattern "%s". Please use a shorter name.', $varName, self::VARIABLE_MAXIMUM_LENGTH, $pattern));
+            }
+
             if ($isSeparator && strlen($precedingText) > 1) {
                 $tokens[] = array('text', substr($precedingText, 0, -1));
             } elseif (!$isSeparator && strlen($precedingText) > 0) {
diff --git a/src/Symfony/Component/Routing/Tests/RouteCompilerTest.php b/src/Symfony/Component/Routing/Tests/RouteCompilerTest.php
index b4b4f45a8379..f08b9688a921 100644
--- a/src/Symfony/Component/Routing/Tests/RouteCompilerTest.php
+++ b/src/Symfony/Component/Routing/Tests/RouteCompilerTest.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\Routing\Tests;
 
 use Symfony\Component\Routing\Route;
+use Symfony\Component\Routing\RouteCompiler;
 
 class RouteCompilerTest extends \PHPUnit_Framework_TestCase
 {
@@ -176,16 +177,16 @@ public function testRouteWithSameVariableTwice()
     }
 
     /**
-     * @dataProvider getNumericVariableNames
+     * @dataProvider getVariableNamesStartingWithADigit
      * @expectedException \DomainException
      */
-    public function testRouteWithNumericVariableName($name)
+    public function testRouteWithVariableNameStartingWithADigit($name)
     {
         $route = new Route('/{'.$name.'}');
         $route->compile();
     }
 
-    public function getNumericVariableNames()
+    public function getVariableNamesStartingWithADigit()
     {
         return array(
            array('09'),
@@ -264,4 +265,13 @@ public function provideCompileWithHostData()
             ),
         );
     }
+
+    /**
+     * @expectedException \DomainException
+     */
+    public function testRouteWithTooLongVariableName()
+    {
+        $route = new Route(sprintf('/{%s}', str_repeat('a', RouteCompiler::VARIABLE_MAXIMUM_LENGTH + 1)));
+        $route->compile();
+    }
 }