diff --git a/AUTHORS b/AUTHORS
index 33d9edd65..7a7850b27 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -72,6 +72,7 @@ The following submitted code, packages or analysis, and deserve special thanks:
   Christoph Robbert
   Oleksii Tsai
   Louis-Claude Canon
+  Jörg Plate
 
 Thanks to the following, who submitted detailed bug reports and excellent
 suggestions:
diff --git a/ChangeLog b/ChangeLog
index 7d5cb5797..bf890a089 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,8 @@
 Features
  + Feature #516, which allows the duplication of completed tasks (thanks to
    Peter De Poorter, Ethan Schoonover).
+ + Applied patch for feature #1005, which prevents the update-holidays.pl script
+   from creating duplicate holidays (thanks to Jörg Plate).
  + Added the new 'indented' format for the 'project' attribute.
  + The 'projects' report now uses 'project.indented' format.
  + The 'summary' report now uses 'project.indented' format.
diff --git a/scripts/add-ons/update-holidays.pl b/scripts/add-ons/update-holidays.pl
index 6a0a2488d..d3c1e9005 100755
--- a/scripts/add-ons/update-holidays.pl
+++ b/scripts/add-ons/update-holidays.pl
@@ -161,6 +161,7 @@ exit (1) if !defined $data || $data eq '';
 # Filter the holidays according to @regions.
 my $id = 1;
 my $content;
+my %seen;
 for my $holiday (split /\n/ms, $data)
 {
   my $parsed = from_json ($holiday);
@@ -172,6 +173,7 @@ for my $holiday (split /\n/ms, $data)
       (@regions > 0 && ($parsed->{'region'} eq '' ||
                         exists $region_hash{$parsed->{'region'}})))
   {
+    next if $seen{ $parsed->{'description'} . ':' . $parsed->{'date'} }++;
     $content .= "holiday.${locale}${id}.name=" . $parsed->{'description'} .  "\n" .
                 "holiday.${locale}${id}.date=" . $parsed->{'date'} .         "\n";
   }