diff --git a/src/pretix/control/templates/pretixcontrol/pdf/index.html b/src/pretix/control/templates/pretixcontrol/pdf/index.html
index f52e65d78b..ee35023d16 100644
--- a/src/pretix/control/templates/pretixcontrol/pdf/index.html
+++ b/src/pretix/control/templates/pretixcontrol/pdf/index.html
@@ -195,7 +195,7 @@
                             <span class="btn btn-default fileinput-button background-button">
                                 <i class="fa fa-upload"></i>
                                 <span>{% trans "Upload custom background" %}</span>
-                                <input id="fileupload" type="file" name="background">
+                                <input id="fileupload" type="file" name="background" accept="application/pdf">
                             </span>
                         </div>
                         <div class="col-sm-12 help-inline">