diff --git a/src/Parse/Processor/Symfony3Processor.php b/src/Parse/Processor/Symfony3Processor.php
index 8eed335a9..bc9085db7 100644
--- a/src/Parse/Processor/Symfony3Processor.php
+++ b/src/Parse/Processor/Symfony3Processor.php
@@ -21,8 +21,8 @@ public function preprocess($text)
 
         foreach ($lines as &$line) {
             // Surround array keys with quotes if not already
-            $line = preg_replace_callback('/^( *)([\'"]{0}[^\'"\n\r:]+[\'"]{0})\s*:/m', function ($matches) {
-                return $matches[1] . '"' . trim($matches[2]) . '":';
+            $line = preg_replace_callback('/^( *)([\'"]{0}[^\'"\n\r:#]+[\'"]{0})\s*:/m', function ($matches) {
+                return $matches[1] . "'" . trim($matches[2]) . "':";
             }, rtrim($line));
         }
 
diff --git a/tests/Parse/YamlTest.php b/tests/Parse/YamlTest.php
index 098af0b43..0e5d63bfc 100644
--- a/tests/Parse/YamlTest.php
+++ b/tests/Parse/YamlTest.php
@@ -144,6 +144,17 @@ public function testSymfony3YamlFileWithProcessor()
                             'false' => false,
                         ],
                     ],
+                    'testClass' => [
+                        'My\Class\Path' => 'value'
+                    ],
+                    'testQuoting' => [
+                        'complex1' => 'this is "very" complex quoting',
+                        'complex2' => 'this is also \'very\' complex quoting',
+                        'middle' => 'this string is "quoted" in the middle',
+                    ],
+                    'testComment' => [
+                        'key' => 'value',
+                    ],
                 ],
             ],
         ], $yaml);
diff --git a/tests/fixtures/yaml/symfony3.yaml b/tests/fixtures/yaml/symfony3.yaml
index a51719f6d..98cd26cde 100644
--- a/tests/fixtures/yaml/symfony3.yaml
+++ b/tests/fixtures/yaml/symfony3.yaml
@@ -29,3 +29,13 @@ form:
             options:
                 true: true
                 false: false
+        testClass:
+            My\Class\Path: value
+        testQuoting:
+            complex1: 'this is "very" complex quoting'
+            complex2: "this is also 'very' complex quoting"
+            middle: this string is "quoted" in the middle
+        testComment:
+            key: value
+           #comment: comments should be removed
+