diff --git a/src/Import/Importer.php b/src/Import/Importer.php
index bff42328f2c5931efed79ad68a22c85a8b02b4ad..4ab6889b418cfe0ef3d703147668d0747bd29049 100644
--- a/src/Import/Importer.php
+++ b/src/Import/Importer.php
@@ -26,23 +26,29 @@ class Importer implements ImporterInterface
         for ($i = 1; $i <= 100; ++$i) {
             try {
                 $files = file_get_contents($this->gitlabRepoTreeUrl.'&access_token='.$this->gitlabRepoToken.'&page='.$i);
-                $files = json_decode($files, true);
 
-                foreach ($files as $file) {
-                    if ([] !== $invalidTeiList && !in_array(trim($file['name']), $invalidTeiList)) {
-                        $teiFileUrl = $this->gitlabProcessedTeiRepoUrl.$file['name'].'?access_token='.$this->gitlabRepoToken.'&ref=master';
-                        $fileData = file_get_contents($teiFileUrl);
-                        if (is_string($fileData)) {
-                            $fileData = json_decode($fileData, true);
+                if (is_string($files)) {
+                    $files = json_decode($files, true);
 
-                            try {
-                                $filesystem->dumpFile($this->teiDir.$file['name'], base64_decode($fileData['content']));
-                            } catch (FileException $exception) {
+                    foreach ($files as $file) {
+                        if ([] !== $invalidTeiList && !in_array(trim($file['name']), $invalidTeiList)) {
+                            $teiFileUrl = $this->gitlabProcessedTeiRepoUrl.$file['name'].'?access_token='.$this->gitlabRepoToken.'&ref=master';
+                            $fileData = file_get_contents($teiFileUrl);
+                            if (is_string($fileData)) {
+                                $fileData = json_decode($fileData, true);
+
+                                try {
+                                    $filesystem->dumpFile(
+                                        $this->teiDir.$file['name'],
+                                        base64_decode($fileData['content'])
+                                    );
+                                } catch (FileException $exception) {
+                                    echo $file['name'].' could not be imported.';
+                                }
+                            } else {
+                                // TODO retry to download the file again
                                 echo $file['name'].' could not be imported.';
                             }
-                        } else {
-                            // TODO retry to download the file again
-                            echo $file['name'].' could not be imported.';
                         }
                     }
                 }