diff --git a/lib/calcms/audio.pm b/lib/calcms/audio.pm
index 1f7853c..5a84c88 100644
--- a/lib/calcms/audio.pm
+++ b/lib/calcms/audio.pm
@@ -100,5 +100,17 @@ sub formatLoudness {
     return qq{<div class="badge-$class">$prefix$value dB</div>};
 }
 
+sub formatFile{
+    my $file     = shift;
+    my $event_id = shift;
+
+    return '' unless $file;
+
+    my ($id) = $file =~ /id(\d+)/;
+    return '' unless $id;
+    return '' if $id eq $event_id;
+    return qq{<div class="badge-error" title="wrong file at playout: $file">Playout</div>};
+}
+
 # do not delete this line
 1;
diff --git a/website/agenda/planung/calendar.cgi b/website/agenda/planung/calendar.cgi
index 3f1137f..95c9eb3 100755
--- a/website/agenda/planung/calendar.cgi
+++ b/website/agenda/planung/calendar.cgi
@@ -1164,6 +1164,7 @@ sub printTableBody {
 
             if ( $event->{class} eq 'event' ) {
                 $event->{content} .= '<br><span class="weak">';
+                $event->{content} .= audio::formatFile($event->{file}, $event->{event_id});
                 $event->{content} .= audio::formatDuration(
                     $event->{duration},
                     $event->{event_duration},