diff --git a/wizard_runreport.py b/wizard_runreport.py
index 621c7d7..183126b 100644
--- a/wizard_runreport.py
+++ b/wizard_runreport.py
@@ -103,8 +103,22 @@ class RunXRechnungReport(Wizard):
         invoices = Invoice.search([
             ('id', '=', data['invoice']),
             ('type', '=', 'out')])
-        to_generate = [x.id for x in invoices if not x.invoice_report_cache]
 
+        # check if stored report is pdf
+        to_delete_report = [
+            x
+            for x in invoices
+            if x.invoice_report_cache and (x.invoice_report_format != 'pdf')]
+
+        # delete reports
+        if to_delete_report:
+            Invoice.write(*[
+                to_delete_report, {
+                    'invoice_report_cache': None,
+                    'invoice_report_cache_id': None,
+                    'invoice_report_format': None}])
+
+        to_generate = [x.id for x in invoices if not x.invoice_report_cache]
         if to_generate:
             report_action = XReport.get_used_report()