diff --git a/RAAspotter.py b/RAAspotter.py
index f7fc686102175ecffe2696e935384d038edf3eb6..db5f831043c9756cedacec7f5861a36f3fe502d3 100644
--- a/RAAspotter.py
+++ b/RAAspotter.py
@@ -309,7 +309,16 @@ class RAAspotter:
 
 
   def ocr(self, raa, retry_on_failure=True):
-    cmd = ['ocrmypdf', '-l', 'eng+fra', '--output-type', 'pdfa', '--redo-ocr', '--skip-big', '500' , f'{self.data_dir}{raa.get_sha256()}.pdf', f'{self.data_dir}{raa.get_sha256()}.pdf']
+    cmd = [
+      'ocrmypdf',
+      '-l', 'eng+fra',
+      '--output-type', 'pdfa',
+      '--redo-ocr',
+      '--skip-big', '500',
+      '--invalidate-digital-signatures',
+      f'{self.data_dir}{raa.get_sha256()}.pdf',
+      f'{self.data_dir}{raa.get_sha256()}.pdf'
+    ]
     logger.debug(f'Lancement de ocrmypdf: {cmd}')
     try:
       output = subprocess.check_output(cmd, stderr=subprocess.STDOUT)