diff --git a/lib/bundler/vendor/thor/lib/thor/shell/basic.rb b/lib/bundler/vendor/thor/lib/thor/shell/basic.rb
index 6ffb21672f..ef97d52ae7 100644
--- a/lib/bundler/vendor/thor/lib/thor/shell/basic.rb
+++ b/lib/bundler/vendor/thor/lib/thor/shell/basic.rb
@@ -425,7 +425,7 @@ class Bundler::Thor
       end
 
       def unix?
-        RUBY_PLATFORM =~ /(aix|darwin|linux|(net|free|open)bsd|cygwin|solaris|irix)/i
+        RUBY_PLATFORM =~ /(aix|darwin|linux|(net|free|open)bsd|cygwin|solaris)/i
       end
 
       def truncate(string, width)