diff --git a/mutant.gemspec b/mutant.gemspec
index 75193970..8241b438 100644
--- a/mutant.gemspec
+++ b/mutant.gemspec
@@ -17,7 +17,7 @@ Gem::Specification.new do |gem|
   gem.executables      = %w[mutant]
 
   gem.add_runtime_dependency('parser',              '~> 2.0.0.pre3')
-  gem.add_runtime_dependency('unparser',            '~> 0.0.12')
+  gem.add_runtime_dependency('unparser',            '~> 0.0.13')
   gem.add_runtime_dependency('ice_nine',            '~> 0.8.0')
   gem.add_runtime_dependency('descendants_tracker', '~> 0.0.1')
   gem.add_runtime_dependency('adamantium',          '~> 0.0.10')