diff --git a/qurator/dinglehopper/ocrd_cli.py b/qurator/dinglehopper/ocrd_cli.py
index b4b31e5..d1e127b 100644
--- a/qurator/dinglehopper/ocrd_cli.py
+++ b/qurator/dinglehopper/ocrd_cli.py
@@ -34,8 +34,8 @@ class OcrdDinglehopperEvaluate(Processor):
         metrics = self.parameter['metrics']
         gt_grp, ocr_grp = self.input_file_grp.split(',')
         for n, page_id in enumerate(self.workspace.mets.physical_pages):
-            gt_file = self.workspace.mets.find_files(fileGrp=gt_grp, pageId=page_id)[0]
-            ocr_file = self.workspace.mets.find_files(fileGrp=ocr_grp, pageId=page_id)[0]
+            gt_file = next(self.workspace.mets.find_files(fileGrp=gt_grp, pageId=page_id))
+            ocr_file = next(self.workspace.mets.find_files(fileGrp=ocr_grp, pageId=page_id))
             gt_file = self.workspace.download_file(gt_file)
             ocr_file = self.workspace.download_file(ocr_file)
             log.info("INPUT FILES %i / %s↔ %s", n, gt_file, ocr_file)
diff --git a/requirements.txt b/requirements.txt
index 57da857..d08539d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,7 +5,7 @@ uniseg
 numpy
 colorama
 MarkupSafe
-ocrd >= 2.13.1
+ocrd >= 2.18.0
 attrs
 multimethod == 1.3  # latest version to officially support Python 3.5
-tqdm
\ No newline at end of file
+tqdm