diff --git a/contactform/label_raffle.py b/contactform/label_raffle.py
index 150e149..db75e07 100644
--- a/contactform/label_raffle.py
+++ b/contactform/label_raffle.py
@@ -11,7 +11,7 @@
 
 
 def print_raffle(form, config, printer_config):
-    label_filename = "label_raffle.png"
+    label_filename = "/tmp/label_raffle.png"
 
     label_css = """
     body, html {
diff --git a/contactform/label_voucher.py b/contactform/label_voucher.py
index 3d7c61b..0a8907e 100644
--- a/contactform/label_voucher.py
+++ b/contactform/label_voucher.py
@@ -15,8 +15,8 @@
 
 
 def print_voucher(form, voucher_code, config, printer_config):
-    label_filename = "label_voucher.png"
-    qr_code_filename = "appuio_voucher_qr.png"
+    label_filename = "/tmp/label_voucher.png"
+    qr_code_filename = "/tmp/appuio_voucher_qr.png"
 
     label_css = """
     body, html {