diff --git a/core/Command/App/CheckCode.php b/core/Command/App/CheckCode.php
index aa618b26cec68754047283304e2770cf6f5345be..1effed9956644e2e25acd85185fb30eca2c56dc2 100644
--- a/core/Command/App/CheckCode.php
+++ b/core/Command/App/CheckCode.php
@@ -28,6 +28,7 @@ namespace OC\Core\Command\App;
 use OC\App\CodeChecker\CodeChecker;
 use OC\App\CodeChecker\EmptyCheck;
 use OC\App\CodeChecker\InfoChecker;
+use OC\App\CodeChecker\LanguageParseChecker;
 use OC\App\InfoParser;
 use Stecman\Component\Symfony\Console\BashCompletion\Completion\CompletionAwareInterface;
 use Stecman\Component\Symfony\Console\BashCompletion\CompletionContext;
@@ -171,6 +172,15 @@ class CheckCode extends Command implements CompletionAwareInterface  {
 			$infoErrors = $infoChecker->analyse($appId);
 
 			$errors = array_merge($errors, $infoErrors);
+
+			$languageParser = new LanguageParseChecker();
+			$languageErrors = $languageParser->analyse($appId);
+
+			foreach ($languageErrors as $languageError) {
+				$output->writeln("<error>$languageError</error>");
+			}
+
+			$errors = array_merge($errors, $languageErrors);
 		}
 
 		$this->analyseUpdateFile($appId, $output);
diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 59cac3db77583b5304a3d5d2672769bcea3acf19..19380f6571b938a44d10475808d35546a53d1dce 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -336,6 +336,7 @@ return array(
     'OC\\App\\CodeChecker\\EmptyCheck' => $baseDir . '/lib/private/App/CodeChecker/EmptyCheck.php',
     'OC\\App\\CodeChecker\\ICheck' => $baseDir . '/lib/private/App/CodeChecker/ICheck.php',
     'OC\\App\\CodeChecker\\InfoChecker' => $baseDir . '/lib/private/App/CodeChecker/InfoChecker.php',
+    'OC\\App\\CodeChecker\\LanguageParseChecker' => $baseDir . '/lib/private/App/CodeChecker/LanguageParseChecker.php',
     'OC\\App\\CodeChecker\\NodeVisitor' => $baseDir . '/lib/private/App/CodeChecker/NodeVisitor.php',
     'OC\\App\\CodeChecker\\PrivateCheck' => $baseDir . '/lib/private/App/CodeChecker/PrivateCheck.php',
     'OC\\App\\CodeChecker\\StrongComparisonCheck' => $baseDir . '/lib/private/App/CodeChecker/StrongComparisonCheck.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index b7e584c324a32699f7ac07cc8198faaea182d947..46285356489741b497b3e162f666f39363dd3d38 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -366,6 +366,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\App\\CodeChecker\\EmptyCheck' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/EmptyCheck.php',
         'OC\\App\\CodeChecker\\ICheck' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/ICheck.php',
         'OC\\App\\CodeChecker\\InfoChecker' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/InfoChecker.php',
+        'OC\\App\\CodeChecker\\LanguageParseChecker' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/LanguageParseChecker.php',
         'OC\\App\\CodeChecker\\NodeVisitor' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/NodeVisitor.php',
         'OC\\App\\CodeChecker\\PrivateCheck' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/PrivateCheck.php',
         'OC\\App\\CodeChecker\\StrongComparisonCheck' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/StrongComparisonCheck.php',
diff --git a/lib/private/App/CodeChecker/LanguageParseChecker.php b/lib/private/App/CodeChecker/LanguageParseChecker.php
new file mode 100644
index 0000000000000000000000000000000000000000..29331d1e648ad57455237e63beec710c67c6843b
--- /dev/null
+++ b/lib/private/App/CodeChecker/LanguageParseChecker.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017, Joas Schilling <coding@schilljs.com>
+ *
+ * @author Joas Schilling <coding@schilljs.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\App\CodeChecker;
+
+class LanguageParseChecker {
+
+	/**
+	 * @param string $appId
+	 * @return array
+	 */
+	public function analyse($appId) {
+		$appPath = \OC_App::getAppPath($appId);
+		if ($appPath === false) {
+			throw new \RuntimeException("No app with given id <$appId> known.");
+		}
+
+		$errors = [];
+		$directory = new \DirectoryIterator($appPath . '/l10n/');
+
+		foreach ($directory as $file) {
+			if ($file->getExtension() !== 'json') {
+				continue;
+			}
+
+			$content = file_get_contents($file->getPathname());
+			json_decode($content, true);
+
+			if (json_last_error() !== JSON_ERROR_NONE) {
+				$errors[] = 'Invalid language file found: l10n/' . $file->getFilename() . ': ' . json_last_error_msg();
+			}
+		}
+
+		return $errors;
+	}
+}