diff --git a/lib/mediainfo.rb b/lib/mediainfo.rb
index 14eae9c..d4dcbe3 100644
--- a/lib/mediainfo.rb
+++ b/lib/mediainfo.rb
@@ -113,6 +113,7 @@ def self.from_uri(input)
   def self.set_singleton_method(object,name,parameters)
     # Handle parameters with invalid characters (instance_variable_set throws error)
     name.gsub!('.','_') if name.include?('.') ## period in name
+    name.gsub!('-','_') if name.include?('-') ## - in name, as in pre-emphasis
     name.downcase!
     # Create singleton_method
     object.instance_variable_set("@#{name}",parameters)