diff --git a/pkgs/development/perl-modules/Unicode-String-perl-5-22.patch b/pkgs/development/perl-modules/Unicode-String-perl-5-22.patch
new file mode 100644
index 00000000000..08d0d13b41f
--- /dev/null
+++ b/pkgs/development/perl-modules/Unicode-String-perl-5-22.patch
@@ -0,0 +1,11 @@
+diff -ru libunicode-string-perl-2.09.pristine/lib/Unicode/CharName.pm libunicode-string-perl-2.09/lib/Unicode/CharName.pm
+--- libunicode-string-perl-2.09.pristine/lib/Unicode/CharName.pm	2005-10-25 19:11:00.000000000 +0100
++++ libunicode-string-perl-2.09/lib/Unicode/CharName.pm	2012-01-24 12:56:59.730653088 +0000
+@@ -77,7 +77,7 @@
+ 	    return join("", "HANGUL SYLLABLE ", @s)
+ 	}
+     }
+-    _init_names() unless defined %NAMES;
++    _init_names() unless %NAMES;
+     $NAMES{sprintf("%04X",$code)}
+ }
diff --git a/pkgs/top-level/perl-packages.nix b/pkgs/top-level/perl-packages.nix
index 6d86f5d3e0e..5568d45e7cf 100644
--- a/pkgs/top-level/perl-packages.nix
+++ b/pkgs/top-level/perl-packages.nix
@@ -13202,6 +13202,9 @@ let self = _self // overrides; _self = with self; {
 
   UnicodeString = buildPerlPackage rec {
     name = "Unicode-String-2.09";
+    patches = [
+      ../development/perl-modules/Unicode-String-perl-5-22.patch
+    ];
     src = fetchurl {
       url = "mirror://cpan/authors/id/G/GA/GAAS/${name}.tar.gz";
       sha256 = "1bgsaf3dgmlgyvi84r42ysc037mr5280amnypa4d98jfjpdvw5y8";