diff --git a/lib/kiss/kiss_serial.rb b/lib/kiss/kiss_serial.rb
index 5a90d70b261dfc07df46c961d2dbedbb8212eb49..b2bf230960f3d4d4355d70ef18834a0b3c8c6405 100644
--- a/lib/kiss/kiss_serial.rb
+++ b/lib/kiss/kiss_serial.rb
@@ -39,6 +39,7 @@ module Kiss
 
         protected
         def write_interface(data)
+            data = data.map { |b| b.chr }.join
             @serial.write(data)
         end