diff --git a/src/Symfony/Component/Yaml/Parser.php b/src/Symfony/Component/Yaml/Parser.php
index 8ffa8ccf64..93b2fca4d7 100644
--- a/src/Symfony/Component/Yaml/Parser.php
+++ b/src/Symfony/Component/Yaml/Parser.php
@@ -491,6 +491,59 @@ class Parser
         return true;
     }
 
+    /**
+     * Substitute from alias where is used a <<
+     *
+     * @param mixed $values Parsed YAML in which aliases are not substituted
+     *
+     * @return mixed YAML with substituted aliases
+     *
+     * @throws Exception\ParseException When indentation problem are detected
+     */
+    private function substituteAliases($values)
+    {
+        if (is_array($values)) {
+            $keys = array();
+            foreach ($values as $key => $value) {
+                if ($key ==='<<' && preg_grep('/^\*.+/', (array) $value) === array_values((array) $value)) {
+                    $values[$key] = array();
+                    foreach ((array) $value as $ref) {
+                        $refName = substr($ref, 1);
+                        if (!array_key_exists($refName, $this->refs)) {
+                            throw new ParseException(
+                                sprintf('Reference "%s" does not exist.', $refName),
+                                $this->getRealCurrentLineNb() + 1,
+                                $this->currentLine
+                            );
+                        }
+
+                        $keys = array_merge(
+                            $keys,
+                            array_diff(array_keys($this->refs[$refName]), $keys)
+                        );
+                        $values[$key] = array_replace($this->refs[$refName], $values[$key]);
+                    }
+                } elseif (!isset($result[$key]) || is_array($result[$key])) {
+                    $keys[] = $key;
+                    $values[$key] = $this->substituteAliases($value);
+                }
+            }
+
+            if (isset($values['<<'])) {
+                $values = array_replace($values['<<'], $values);
+                unset($values['<<']);
+                uksort(
+                    $values,
+                    function ($a, $b) use ($keys) {
+                        return array_search($a, $keys, true) - array_search($b, $keys, true);
+                    }
+                );
+            }
+        }
+
+        return $values;
+    }
+
     /**
      * Parses a YAML value.
      *
@@ -526,7 +579,7 @@ class Parser
         }
 
         try {
-            return Inline::parse($value, $exceptionOnInvalidType, $objectSupport, $objectForMap, $this->refs);
+            return $this->substituteAliases(Inline::parse($value, $exceptionOnInvalidType, $objectSupport, $objectForMap, $this->refs));
         } catch (ParseException $e) {
             $e->setParsedLine($this->getRealCurrentLineNb() + 1);
             $e->setSnippet($this->currentLine);
diff --git a/src/Symfony/Component/Yaml/Tests/Fixtures/sfMergeKey.yml b/src/Symfony/Component/Yaml/Tests/Fixtures/sfMergeKey.yml
index 59f6125141..a37eca2e3c 100644
--- a/src/Symfony/Component/Yaml/Tests/Fixtures/sfMergeKey.yml
+++ b/src/Symfony/Component/Yaml/Tests/Fixtures/sfMergeKey.yml
@@ -22,6 +22,7 @@ yaml: |
             foo: bar
             foo: ignore
             bar: foo
+    bar_inline: {a: before, d: other, <<: *foo, b: new, x: Oren, c: { foo: bar, foo: ignore, bar: foo}}
     duplicate:
         foo: bar
         foo: ignore
@@ -46,15 +47,20 @@ yaml: |
             p: 12345
         z:
             <<: *nestedref
+    head_inline: &head_inline { <<: [ *foo , *dong , *foo2 ] }
+    recursive_inline: { <<: *head_inline, c: { <<: *foo2 } }
 php: |
     array(
         'foo' => array('a' => 'Steve', 'b' => 'Clark', 'c' => 'Brian', 'e' => 'notnull'),
         'bar' => array('a' => 'before', 'd' => 'other', 'e' => null, 'b' => 'new', 'c' => array('foo' => 'bar', 'bar' => 'foo'), 'x' => 'Oren'),
+        'bar_inline' => array('a' => 'before', 'd' => 'other', 'b' => 'new', 'c' => array('foo' => 'bar', 'bar' => 'foo'), 'x' => 'Oren'),
         'duplicate' => array('foo' => 'bar'),
         'foo2' => array('a' => 'Ballmer'),
         'ding' => array('fi', 'fei', 'fo', 'fam'),
         'check' => array('a' => 'Steve', 'b' => 'Clark', 'c' => 'Brian', 'e' => 'notnull', 'fi', 'fei', 'fo', 'fam', 'isit' => 'tested'),
         'head' => array('a' => 'Steve', 'b' => 'Clark', 'c' => 'Brian', 'e' => 'notnull', 'fi', 'fei', 'fo', 'fam'),
         'taz' => array('a' => 'Steve', 'w' => array('p' => 1234)),
-        'nested' => array('a' => 'Steve', 'w' => array('p' => 12345), 'd' => 'Doug', 'z' => array('p' => 12345))
+        'nested' => array('a' => 'Steve', 'w' => array('p' => 12345), 'd' => 'Doug', 'z' => array('p' => 12345)),
+        'head_inline' => array('a' => 'Steve', 'b' => 'Clark', 'c' => 'Brian', 'fi', 'fei', 'fo', 'fam'),
+        'recursive_inline' => array('a' => 'Steve', 'b' => 'Clark', 'c' => array('a' => 'Ballmer'), 'fi', 'fei', 'fo', 'fam')
     )
diff --git a/src/Symfony/Component/Yaml/Tests/ParserTest.php b/src/Symfony/Component/Yaml/Tests/ParserTest.php
index 9be278f67e..97ce0cac0f 100644
--- a/src/Symfony/Component/Yaml/Tests/ParserTest.php
+++ b/src/Symfony/Component/Yaml/Tests/ParserTest.php
@@ -1207,6 +1207,18 @@ YAML;
 
         $this->assertSame($expected, $this->parser->parse($yaml));
     }
+
+    /**
+     * @expectedException \Symfony\Component\Yaml\Exception\ParseException
+     * @expectedExceptionMessage Reference "foo" does not exist
+     */
+    public function testEvalRefException()
+    {
+        $yaml = <<<EOE
+foo: { &foo { a: Steve, <<: *foo} }
+EOE;
+        $this->parser->parse($yaml);
+    }
 }
 
 class B