diff --git a/ChangeLog b/ChangeLog
index fb67f342ef..022539a65f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Dec 25 14:11:57 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* io.c (io_encoding_set): missing return type.
+
 Tue Dec 25 14:03:48 2007  NARUSE, Yui <naruse@ruby-lang.org>
 
 	* test/rinda/test_rinda.rb (MockClock#{_forward, forwrd, sleep}):
diff --git a/io.c b/io.c
index 5edc26540c..4b392b8d27 100644
--- a/io.c
+++ b/io.c
@@ -1360,7 +1360,8 @@ read_all(rb_io_t *fptr, long siz, VALUE str)
     return io_enc_str(str, fptr);
 }
 
-void rb_io_set_nonblock(rb_io_t *fptr)
+void
+rb_io_set_nonblock(rb_io_t *fptr)
 {
     int flags;
 #ifdef F_GETFL
@@ -5605,6 +5606,7 @@ io_new_instance(VALUE args)
     return rb_class_new_instance(2, (VALUE*)args+1, *(VALUE*)args);
 }
 
+static void
 io_encoding_set(rb_io_t *fptr, int argc, VALUE v1, VALUE v2)
 {
     if (argc == 2) {