1 files changed, 1 insertions, 1 deletions
diff --git a/io.c b/io.c
index 32a37df3c9..749229e335 100644
--- a/io.c
+++ b/io.c
@@ -5853,7 +5853,7 @@ open_key_args(int argc, VALUE *argv, struct foreach_arg *arg)
 
 	arg->io = rb_io_open(RSTRING_PTR(argv[0]), "r");
 	GetOpenFile(arg->io, fptr);
-	fptr->enc = rb_to_encoding(v);
+        mode_enc(fptr, StringValueCStr(v));
 	return;
     }
 }