diff --git a/lib/git/lib.rb b/lib/git/lib.rb
index 777e42ea..36e36845 100644
--- a/lib/git/lib.rb
+++ b/lib/git/lib.rb
@@ -859,10 +859,7 @@ def meets_required_version?
 
     def command_lines(cmd, opts = [], chdir = true, redirect = '')
       cmd_op = command(cmd, opts, chdir)
-      op = cmd_op.encode("UTF-8", "binary", {
-	  	:invalid => :replace,
-		:undef => :replace
-	  })
+      op = cmd_op.chars.map { |c| c.valid_encoding? && c || '�' }.join
       op.split("\n")
     end