diff --git a/Changes b/Changes
index 61aeaba..13d40fb 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,6 @@
-0.31 2017-06-29
+0.31 2017-06-30
         - Fixed exit codes in script.
+        - Use CORE::fc for case folding.
 
 0.30 2017-06-19
         - Fixed permission handling in test suite.
diff --git a/Makefile.PL b/Makefile.PL
index af7b1d3..e59ff5e 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -28,7 +28,6 @@
     'File::Temp'      => 0,
     'Directory::Iterator' => 0,
     'Benchmark'       => 0,
-    'Unicode::CaseFold' => 1.00,
     'Unicode::Normalize' => 0,
     'Carp'            => 0,
     'strict'          => 0,
diff --git a/lib/KorAP/XML/Tokenizer.pm b/lib/KorAP/XML/Tokenizer.pm
index 067dc70..40e6c63 100644
--- a/lib/KorAP/XML/Tokenizer.pm
+++ b/lib/KorAP/XML/Tokenizer.pm
@@ -1,5 +1,6 @@
 package KorAP::XML::Tokenizer;
 use Mojo::Base -base;
+use feature 'fc';
 use Mojo::ByteStream 'b';
 use Mojo::File;
 use XML::Fast;
@@ -11,7 +12,6 @@
 use KorAP::XML::Tokenizer::Spans;
 use KorAP::XML::Tokenizer::Tokens;
 use KorAP::XML::Index::MultiTermTokenStream;
-use Unicode::CaseFold;
 use Unicode::Normalize qw/getCombinClass normalize/;
 use List::MoreUtils 'uniq';
 use JSON::XS;