diff --git a/src/Symfony/Component/Console/Tests/Helper/TableTest.php b/src/Symfony/Component/Console/Tests/Helper/TableTest.php
index 375f39f7d0..1497e866a9 100644
--- a/src/Symfony/Component/Console/Tests/Helper/TableTest.php
+++ b/src/Symfony/Component/Console/Tests/Helper/TableTest.php
@@ -116,11 +116,11 @@ TABLE
                 $books,
                 'compact',
 <<<'TABLE'
- ISBN          Title                    Author
- 99921-58-10-7 Divine Comedy            Dante Alighieri
- 9971-5-0210-0 A Tale of Two Cities     Charles Dickens
- 960-425-059-0 The Lord of the Rings    J. R. R. Tolkien
- 80-902734-1-6 And Then There Were None Agatha Christie
+ ISBN          Title                    Author           
+ 99921-58-10-7 Divine Comedy            Dante Alighieri  
+ 9971-5-0210-0 A Tale of Two Cities     Charles Dickens  
+ 960-425-059-0 The Lord of the Rings    J. R. R. Tolkien 
+ 80-902734-1-6 And Then There Were None Agatha Christie  
 
 TABLE
             ],
@@ -129,14 +129,14 @@ TABLE
                 $books,
                 'borderless',
 <<<'TABLE'
- =============== ========================== ==================
-  ISBN            Title                      Author
- =============== ========================== ==================
-  99921-58-10-7   Divine Comedy              Dante Alighieri
-  9971-5-0210-0   A Tale of Two Cities       Charles Dickens
-  960-425-059-0   The Lord of the Rings      J. R. R. Tolkien
-  80-902734-1-6   And Then There Were None   Agatha Christie
- =============== ========================== ==================
+ =============== ========================== ================== 
+  ISBN            Title                      Author            
+ =============== ========================== ================== 
+  99921-58-10-7   Divine Comedy              Dante Alighieri   
+  9971-5-0210-0   A Tale of Two Cities       Charles Dickens   
+  960-425-059-0   The Lord of the Rings      J. R. R. Tolkien  
+  80-902734-1-6   And Then There Were None   Agatha Christie   
+ =============== ========================== ================== 
 
 TABLE
             ],
diff --git a/src/Symfony/Component/Yaml/Parser.php b/src/Symfony/Component/Yaml/Parser.php
index fc85a78e2d..e51391f35d 100644
--- a/src/Symfony/Component/Yaml/Parser.php
+++ b/src/Symfony/Component/Yaml/Parser.php
@@ -670,7 +670,7 @@ class Parser
         if (\in_array($value[0], ['!', '|', '>'], true) && self::preg_match('/^(?:'.self::TAG_PATTERN.' +)?'.self::BLOCK_SCALAR_HEADER_PATTERN.'$/', $value, $matches)) {
             $modifiers = isset($matches['modifiers']) ? $matches['modifiers'] : '';
 
-            $data = $this->parseBlockScalar($matches['separator'], preg_replace('#\d+#', '', $modifiers), (int) abs($modifiers));
+            $data = $this->parseBlockScalar($matches['separator'], preg_replace('#\d+#', '', $modifiers), (int) abs((int) $modifiers));
 
             if ('' !== $matches['tag'] && '!' !== $matches['tag']) {
                 if ('!!binary' === $matches['tag']) {
diff --git a/src/Symfony/Component/Yaml/Tests/ParserTest.php b/src/Symfony/Component/Yaml/Tests/ParserTest.php
index 2524f39a86..1ce99468c4 100644
--- a/src/Symfony/Component/Yaml/Tests/ParserTest.php
+++ b/src/Symfony/Component/Yaml/Tests/ParserTest.php
@@ -2108,6 +2108,48 @@ YAML;
 
         $this->assertSame(['parameters' => 'abc'], $this->parser->parse($yaml));
     }
+
+    public function testParseValueWithModifiers()
+    {
+        $yaml = <<<YAML
+parameters:
+    abc: |+5 # plus five spaces indent
+         one
+         two
+         three
+         four
+         five
+YAML;
+        $this->assertSame(
+            [
+                'parameters' => [
+                    'abc' => implode("\n", ['one', 'two', 'three', 'four', 'five']),
+                ],
+            ],
+            $this->parser->parse($yaml)
+        );
+    }
+
+    public function testParseValueWithNegativeModifiers()
+    {
+        $yaml = <<<YAML
+parameters:
+    abc: |-3 # minus
+       one
+       two
+       three
+       four
+       five
+YAML;
+        $this->assertSame(
+            [
+                'parameters' => [
+                    'abc' => implode("\n", ['one', 'two', 'three', 'four', 'five']),
+                ],
+            ],
+            $this->parser->parse($yaml)
+        );
+    }
 }
 
 class B